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4.0

Jun 29, 2018
06/18

by
Chris O'Brien; Tian Zhong; Andrei Faraon; Christoph Simon

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We study the possibility of using single rare-earth ions coupled to a photonic cavity with high cooperativity for performing non-destructive measurements of photons, which would be useful for global quantum networks and photonic quantum computing. We calculate the achievable fidelity as a function of the parameters of the rare-earth ion and photonic cavity, which include the ion's optical and spin dephasing rates, the cavity linewidth, the single photon coupling to the cavity, and the detection...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1608.06679

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5.0

Jun 29, 2018
06/18

by
Guanglei Wang; Hongya Xu; Liang Huang; Ying-Cheng Lai

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Zitterbewegung (ZB) is a phenomenon in relativistic quantum systems where the electron wave packet exhibits a trembling or oscillating behavior during its motion, caused by its interaction or coupling with the negative energy state. To directly observe ZB in electronic systems is difficult, due to the challenges associated with the atomic scale wavelength of the electron. Photonic systems offer an alternative paradigm. We exploit the concept of pseudo parity-time (pseudo PT ) symmetry to study...

Topics: Quantum Physics, Optics, Physics

Source: http://arxiv.org/abs/1612.07825

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4.0

Jun 30, 2018
06/18

by
Slobodan Prvanovic

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Within the framework of self-adjoint operator of time in non-relativistic quantum mechanics the equation describing change of the state of quantum system with respect to energy is introduced. The operator of time appears to be the generator of the change of energy while the operator of energy, that is conjugate to the operator of time, generates time evolution in this proposal. Two examples, one with discrete time and the other with continuous one, are given and the generalization of...

Topics: General Relativity and Quantum Cosmology, Quantum Physics

Source: http://arxiv.org/abs/1701.05244

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2.0

Jun 30, 2018
06/18

by
Sarah Croke; Stephen M Barnett

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Non-locality without entanglement is a rather counter-intuitive phenomenon in which information may be encoded entirely in product (unentangled) states of composite quantum systems in such a way that local measurement of the subsystems is not enough for optimal decoding. For simple examples of pure product states, the gap in performance is known to be rather small when arbitrary local strategies are allowed. Here we restrict to local strategies readily achievable with current technology; those...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1701.02579

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2.0

Jun 28, 2018
06/18

by
C. D. Bruzewicz; R. McConnell; J. Chiaverini; J. M. Sage

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We describe rapid, random-access loading of a two-dimensional (2D) surface-electrode ion-trap array based on two crossed photo-ionization laser beams. With the use of a continuous flux of pre-cooled neutral atoms from a remotely-located source, we achieve loading of a single ion per site while maintaining long trap lifetimes and without disturbing the coherence of an ion quantum bit in an adjacent site. This demonstration satisfies all major criteria necessary for loading and reloading...

Topics: Quantum Physics, Atomic Physics, Physics

Source: http://arxiv.org/abs/1511.03293

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4.0

Jun 29, 2018
06/18

by
Anas Othman

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In this paper we define and study a new class of states (the empty states). These states are the superposition of two identical states (self-superposition state). We defined three different representations of theses states, namely, the source, the operator, and the self-superposition representations. Then, we apply the empty state to an elementary example state and find its three different representations. We apply the empty state to Fock states and find an undetermined state. Then, we apply...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1602.03797

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3.0

Jun 29, 2018
06/18

by
Chang Jian Kwong; Simone Felicetti; Leong Chuan Kwek; Joonwoo Bae

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Entanglement is not only fundamental for understanding multipartite quantum systems but also generally useful for quantum information applications. Despite much effort devoted so far, little is known about minimal resources for detecting entanglement and also comparisons to tomography which reveals the full characterization. Here, we show that all entangled states can in general be detected in an experimental scheme that estimates the fidelity of two pure quantum states. An experimental...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1606.00427

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3.0

Jun 30, 2018
06/18

by
Yongjun Ma; Jiaxiang Wang; Xinye Xu; Qi Wei; Sabre Kais

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In this paper, we have studied the one-dimensional commensurate quantum Frenkel-Kontorova model by a density-matrix renormalization group (DMRG) algorithm. The focus has been on its properties of the entanglement, the coordinate correlation, the ground state energy and the energy gap between the ground state and the first excited one. It is demonstrated that a quantum phase transition (QPT) between the pinned and the sliding phases takes place as the quantum fluctuation, measured by an...

Topics: Quantum Physics, Statistical Mechanics, Condensed Matter

Source: http://arxiv.org/abs/1405.2901

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3.0

Jun 29, 2018
06/18

by
Jayashree HV; Himanshu Thapliyal; Hamid R. Arabnia; V K Agrawal

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A reversible logic has application in quantum computing. A reversible logic design needs resources such as ancilla and garbage qubits to reconfigure circuit functions or gate functions. The removal of garbage qubits and ancilla qubits are essential in designing an efficient quantum circuit. In the literature, there are multiple designs that have been proposed for a reversible multiplication operation. A multiplication hardware is essential for the circuit design of quantum algorithms, quantum...

Topics: Emerging Technologies, Quantum Physics, Computing Research Repository

Source: http://arxiv.org/abs/1608.01228

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4.0

Jun 30, 2018
06/18

by
Laleh Safari; Pedro Amaro; Jose Paulo Santos; Filippo Fratini

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The amplitude of two-photon transitions between hyperfine states in hydrogenlike ions is derived based on relativistic Dirac equation and second order perturbation theory. We study angular and linear polarization properties of the photon pair emitted in the decay of $2s$ states, where spin-flip and non-spin-flip transitions are highlighted. We pay particular attention to hydrogenlike uranium, since it is an ideal candidate for investigating relativistic and high-multipole effects, such as...

Topics: Physics, Quantum Physics, Atomic Physics

Source: http://arxiv.org/abs/1407.4063

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4.0

Jun 30, 2018
06/18

by
Nicola Bartolo; David J. Papoular; Alessio Recati; Chiara Menotti

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We discuss the properties of the effective dipolar interaction for two particles tightly confined along a one-dimensional tube, stressing the emergence of a single dipolar-induced resonance in a regime for which two classical dipoles would just repel each other. We present a toy-model potential reproducing the main features of the effective interaction: a non-zero-range repulsive potential competing with an attractive contact term. The existence of a single resonance is confirmed analytically....

Topics: Quantum Gases, Quantum Physics, Condensed Matter

Source: http://arxiv.org/abs/1410.2483

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5.0

Jun 29, 2018
06/18

by
M. Balamurugan; R. Chakrabarti; B. Virgin Jenisha

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We study the evolution of the hybrid entangled squeezed states of the qubit-oscillator system in the strong coupling domain. Following the adiabatic approximation we obtain the reduced density matrices of the qubit and the oscillator degrees of freedom. The oscillator reduced density matrix is utilized to calculate the quasiprobability distributions such as the Sudarshan-Glauber diagonal P -representation, the Wigner W -distribution, and the nonnegative Husimi Q-function. The negativity...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1610.05117

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3.0

Jun 30, 2018
06/18

by
Tamoghna Das; Asutosh Kumar; Amit Kumar Pal; Namrata Shukla; Aditi Sen De; Ujjwal Sen

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Distilling highly entangled quantum states from weaker ones is a process that is crucial for efficient and long-distance quantum communication, and has implications for several other quantum information protocols. We introduce the notion of distillation under limited resources, and specifically focus on the energy constraint. The corresponding protocol, which we call the canonical distillation of entanglement, naturally leads to the set of canonically distillable states. We show that for...

Topics: Quantum Physics, Statistical Mechanics, Condensed Matter

Source: http://arxiv.org/abs/1411.7936

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4.0

Jun 30, 2018
06/18

by
Tristan Farrow; Vlatko Vedral

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A generic and intuitive model for coherent energy transport in multiple minima systems coupled to a quantum mechanical bath is shown. Using a simple spin-boson system, we illustrate how a generic donor-acceptor system can be brought into resonance using a narrow band of vibrational modes, such that the transfer efficiency of an electron-hole pair (exciton) is made arbitrarily high. Coherent transport phenomena in nature are of renewed interest since the discovery that a photon captured by the...

Topics: Biological Physics, Physics, Chemical Physics, Quantum Physics

Source: http://arxiv.org/abs/1406.5530

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2.0

Jun 29, 2018
06/18

by
Radhakrishnan Balu; Daniel Castillo; George Siopsis; Christian Weedbrook

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We derive the continuous-time limit of discrete quantum walks with topological phases. We show the existence of a continuous-time limit that preserves their topological phases. We consider both simple-step and split-step walks, and derive analytically equations of motion governing their behavior. We obtain simple analytical solutions showing the existence of bound states at the boundary of two phases, and solve the equations of motion numerically in the bulk.

Topic: Quantum Physics

Source: http://arxiv.org/abs/1611.07457

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2.0

Jun 30, 2018
06/18

by
Ching-Kit Chan; Guin-Dar Lin; Susanne F. Yelin; Mikhail D. Lukin

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When a quantum system interacts with multiple reservoirs, the environmental effects are usually treated in an additive manner. We show that this assumption breaks down for non-Markovian environments that have finite memory times. Specifically, we demonstrate that quantum interferences between independent environments can qualitatively modify the dynamics of the physical system. We illustrate this effect with a two level system coupled to two structured photonic reservoirs, discuss its origin...

Topics: Quantum Physics, Quantum Gases, Condensed Matter

Source: http://arxiv.org/abs/1402.3289

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2.0

Jun 28, 2018
06/18

by
Nils Trautmann; Gernot Alber

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We propose a scheme for triggering a dissipation dominated highly efficient excitation transfer from a single photon wave packet to a single quantum emitter. This single photon induced optical pumping turns dominant dissipative processes, such as spontaneous photon emission by the emitter or cavity decay, into valuable tools for quantum information processing and quantum communication. It works for an arbitrarily shaped single photon wave packet with sufficiently small bandwidth provided a...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1512.01371

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5.0

Jun 29, 2018
06/18

by
John M. Myers; F. Hadi Madjid

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The basic equations of physics involve a time variable t and are invariant under the transformation $t goes to -t$. This invariance at first sight appears to impose time reversibility as a principle of physics, in conflict with thermodynamics. But equations written on the blackboard are not the whole story in physics. In prior work we sharpened a distinction obscured in today's theoretical physics, the distinction between obtaining evidence from experiments on the laboratory bench and...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1604.06771

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6.0

Jun 29, 2018
06/18

by
Matthias Christandl; Roberto Ferrara

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We derive a formal connection between quantum data hiding and quantum privacy, confirming the intuition behind the construction of bound entangled states from which secret bits can be extracted. We present three main results. First, we show how to simplify the class of private states and related states via reversible local operation and one-way communication. Second, we obtain a bound on the one-way distillable entanglement of private states in terms of restricted relative entropy measures,...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1609.04696

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5.0

Jun 29, 2018
06/18

by
Ashutosh K. Goswami; Prasanta K. Panigrahi

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We investigate the Peres-Horodecki positive partial transpose (PPT) criterion in the context of conserved quantities and derive a condition of in- separability for a composite bipartite system depending only on the dimen- sions of its subsystems, which leads to a bi-linear entanglement witness for the two qubit system. A separability inequality using generalized Schrodinger- Robertson uncertainty relation taking suitable operators, has been derived, which proves to be stronger than the...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1608.01177

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4.0

Jun 29, 2018
06/18

by
R. E. Kastner

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The Transactional Interpretation has been subject at various times to a challenge based on a type of thought experiment first proposed by Maudlin. It has been argued by several authors that such experiments do not in fact constitute a significant problem for the transactional picture. The purpose of this work is to point out that, when the relativistic level of the interpretation is considered, Maudlin-type challenges cannot even be mounted, since the putative 'slow-moving offer wave,' taken as...

Topics: Quantum Physics, History and Philosophy of Physics, Physics

Source: http://arxiv.org/abs/1610.04609

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2.0

Jun 29, 2018
06/18

by
Harald Homulle; Stefan Visser; Bishnu Patra; Giorgio Ferrari; Enrico Prati; Fabio Sebastiano; Edoardo Charbon

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Recent advances in solid-state qubit technology are paving the way to fault-tolerant quantum computing systems. However, qubit technology is limited by qubit coherence time and by the complexity of coupling the quantum system with a classical electronic infrastructure. We propose an infrastructure, enabling to read and control qubits, that is implemented on a field-programmable gate array (FPGA). The FPGA platform supports functionality required by several qubit technologies and can operate...

Topics: Quantum Physics, Physics, Instrumentation and Detectors

Source: http://arxiv.org/abs/1602.05786

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Jun 28, 2018
06/18

by
E. Chitambar; A. Streltsov; S. Rana; M. N. Bera; G. Adesso; M. Lewenstein

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We introduce and study the task of assisted coherence distillation. This task arises naturally in bipartite systems where both parties work together to generate the maximal possible coherence on one of the subsystems. Only incoherent operations are allowed on the target system while general local quantum operations are permitted on the other, an operational paradigm that we call local quantum-incoherent operations and classical communication (LQICC). We show that the asymptotic rate of assisted...

Topics: Quantum Physics, Mathematical Physics, High Energy Physics - Theory, Statistical Mechanics,...

Source: http://arxiv.org/abs/1507.08171

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2.0

Jun 28, 2018
06/18

by
Stephen Choi; Roberto Onofrio; Bala Sundaram

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We consider an Ehrenfest approximation for a particle in a double-well potential in the presence of an external environment schematized as a finite resource heat bath. This allows us to explore how the limitations in the applicability of Ehrenfest dynamics to nonlinear systems are modified in an open system setting. Within this framework, we have identified an environment-induced spontaneous symmetry breaking mechanism, and we argue that the Ehrenfest approximation becomes increasingly valid in...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1510.02156

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3.0

Jun 29, 2018
06/18

by
Y. Y. Atas; I. Bouchoule; D. M. Gangardt; K. V. Kheruntsyan

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We analyse the breathing-mode oscillations of a harmonically quenched Tonks-Giradeau (TG) gas using an exact finite-temperature dynamical theory. We predict a striking collective manifestation of impenetrability---a collective many-body bounce effect. The effect, while being invisible in the evolution of the in-situ density profile of the gas, can be revealed through a nontrivial periodic narrowing of its momentum distribution, taking place at twice the rate of the fundamental breathing-mode...

Topics: Quantum Physics, Condensed Matter, Quantum Gases

Source: http://arxiv.org/abs/1612.04593

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3.0

Jun 30, 2018
06/18

by
A. S. Sheremet; D. F. Kornovan; L. V. Gerasimov; B. Gouraud; J. Laurat; D. V. Kupriyanov

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Light transport in a dense and disordered cold atomic ensemble, where the cooperation of atomic dipoles essentially modifies their coupling with the radiation modes, offers an alternative approach to light-matter interfacing protocols. Here, we show how the cooperativity and quasi-static dipole interaction affect the process of light propagation under the conditions of electromagnetically-induced transparency (EIT). We perform comparative analysis of the self-consistent approach with ab-initio...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1411.4771

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4.0

Jun 28, 2018
06/18

by
Anand Natarajan; Thomas Vidick

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$ \newcommand{\Xlin}{\mathcal{X}} \newcommand{\Zlin}{\mathcal{Z}} \newcommand{\C}{\mathbb{C}} $We give a quantum multiprover interactive proof system for the local Hamiltonian problem in which there is a constant number of provers, questions are classical of length polynomial in the number of qubits, and answers are of constant length. The main novelty of our protocol is that the gap between completeness and soundness is directly proportional to the promise gap on the (normalized) ground state...

Topics: Quantum Physics, Computational Complexity, Computing Research Repository

Source: http://arxiv.org/abs/1512.02090

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Jun 27, 2018
06/18

by
P. Jurcevic; P. Hauke; C. Maier; C. Hempel; B. P. Lanyon; R. Blatt; C. F. Roos

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The static and dynamic properties of many-body quantum systems are often well described by collective excitations, known as quasiparticles. Engineered quantum systems offer the opportunity to study such emergent phenomena in a precisely controlled and otherwise inaccessible way. We present a spectroscopic technique to study artificial quantum matter and use it for characterizing quasiparticles in a many-body system of trapped atomic ions. Our approach is to excite combinations of the system's...

Topics: Quantum Physics, Quantum Gases, Condensed Matter

Source: http://arxiv.org/abs/1505.02066

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4.0

Jun 29, 2018
06/18

by
Virginia Feldman; Jonas Maziero; A. Auyuanet

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In this article, by considering Bell-diagonal two-qubit initial states submitted to local dynamics generated by the phase damping, bit flip, phase flip, bit-phase flip, and depolarizing channels, we report some elegant direct-dynamical relations between geometric measures of entanglement and discord. The complex scenario appearing already in this simplified case study indicates that similarly simple relation shall hardly be found in more general situations.

Topics: Information Theory, Quantum Physics, Computing Research Repository, Mathematics

Source: http://arxiv.org/abs/1610.09030

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2.0

Jun 29, 2018
06/18

by
Troy Lee; Anupam Prakash; Ronald de Wolf; Henry Yuen

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We study how well functions over the boolean hypercube of the form $f_k(x)=(|x|-k)(|x|-k-1)$ can be approximated by sums of squares of low-degree polynomials, obtaining good bounds for the case of approximation in $\ell_{\infty}$-norm as well as in $\ell_1$-norm. We describe three complexity-theoretic applications: (1) a proof that the recent breakthrough lower bound of Lee, Raghavendra, and Steurer on the positive semidefinite extension complexity of the correlation and TSP polytopes cannot be...

Topics: Quantum Physics, Computational Complexity, Computing Research Repository

Source: http://arxiv.org/abs/1601.02311

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4.0

Jun 30, 2018
06/18

by
Kok Chuan Tan; Tyler Volkoff; Hyukjoon Kwon; Hyunseok Jeong

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In this paper, we detail an orthogonalization procedure that allows for the quantification of the amount of coherence present an arbitrary superposition of coherent states. The present construction is based on the quantum coherence resource theory introduced by Baumgratz et al., and the coherence resource monotone that we identify is found to characterize the nonclassicality traditionally analyzed via the Glauber-Sudarshan $P$ distribution. This suggests that identical quantum resources...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1703.01067

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2.0

Jun 29, 2018
06/18

by
Jiaxiang Zhang; Eugenio Zallo; Bianca Höfer; Yan Chen; Robert Keil; Michael Zopf; Stefan Böttner; Fei Ding; Oliver G. Schmidt

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The scalability of quantum dot based non-classical light sources relies on the control over their dissimilar emission energies. Electric fields offer a promising route to tune the quantum dot emission energy through the quantum-confined Stark effect. However, electric fields have been mostly used for tuning the energy of single-photon emission from quantum dots, while electrical control over the energy of entangled-photon emission, which is crucial for building a solid-state quantum repeater...

Topics: Mesoscale and Nanoscale Physics, Optics, Condensed Matter, Physics, Quantum Physics

Source: http://arxiv.org/abs/1604.04501

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3.0

Jun 30, 2018
06/18

by
Leander Fiedler; Pieter Naaijkens

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We prove Haag duality for conelike regions in the ground state representation corresponding to the translational invariant ground state of Kitaev's quantum double model for finite abelian groups. This property says that if an observable commutes with all observables localised outside the cone region, it actually is an element of the von Neumann algebra generated by the local observables inside the cone. This strengthens locality, which says that observables localised in disjoint regions...

Topics: Quantum Physics, Mathematics, Mathematical Physics, Operator Algebras

Source: http://arxiv.org/abs/1406.1084

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3.0

Jun 29, 2018
06/18

by
Marco Pezzutto; Mauro Paternostro; Yasser Omar

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We study the dynamics of a spin-1/2 particle interacting with a multi-spin environment, modelling the corresponding open system dynamics through a collision-based model. The environmental particles are prepared in individual thermal states, and we investigate the effects of a distribution of temperatures across the spin environment on the evolution of the system, particularly how thermalisation in the long-time limit is affected. %We also address the conditions under which the system reaches a...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1608.03497

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2.0

Jun 29, 2018
06/18

by
J. K. Korbicz; E. A. Aguilar; P. Ćwikliński; P. Horodecki

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Measurement is of central interest in quantum mechanics as it provides the link between the quantum world and the world of everyday experience. One of the features of the latter is its robust, objective character, contrasting the delicate nature of quantum systems. Here we analyze in a model-independent way a measurement process and give an affirmative answer to the question posed in the title, provided we coarse-grain the measuring apparatus and we wait long enough. As a typicality measure we...

Topics: Quantum Physics, Statistical Mechanics, Condensed Matter

Source: http://arxiv.org/abs/1604.02011

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4.0

Jun 30, 2018
06/18

by
Emanuele Levi; Igor Lesanovsky

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We introduce a class of spin models with long-range interactions---in the sense that they extend significantly beyond nearest neighbors---whose ground states can be constructed analytically and have a simple matrix product state representation. This enables the detailed study of ground state properties, such as correlation functions and entanglement, in the thermodynamic limit. The spin models presented here are closely related to lattice gases of strongly interacting polar molecules or Rydberg...

Topics: Physics, Quantum Physics, Atomic Physics, Strongly Correlated Electrons, Condensed Matter

Source: http://arxiv.org/abs/1403.2866

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2.0

Jun 30, 2018
06/18

by
Avijit Misra; Anindya Biswas; Arun K. Pati; Aditi Sen De; Ujjwal Sen

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Quantum discord is a measure of quantum correlations beyond the entanglement-separability paradigm. It is conceptualized by using the von Neumann entropy as a measure of disorder. We introduce a class of quantum correlation measures as differences between total and classical correlations, in a shared quantum state, in terms of the sandwiched relative R\'{e}nyi and Tsallis entropies. We compare our results with those obtained by using the traditional relative entropies. We find that the measures...

Topics: Quantum Physics, Strongly Correlated Electrons, Condensed Matter

Source: http://arxiv.org/abs/1406.5065

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3.0

Jun 29, 2018
06/18

by
Zurika Blanco-Garcia; Oscar Rosas-Ortiz

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We substitute the fully absorbing obstacle in the Elitzur-Vaidman experiment by a semitransparent object and show that the probabilities of detection can be manipulated in dependence of the transparency of such an object. Then, we connect our results with the delayed choice experiment proposed by Wheeler. It is found that the transparency of the obstacle determines either a particle-like or a wave-like behaviour of a test photon.

Topic: Quantum Physics

Source: http://arxiv.org/abs/1605.01084

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2.0

Jun 30, 2018
06/18

by
Ting Wu; Renyuan Liao

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We consider two-component Bose-Einstein condensates subject to Weyl spin-orbit coupling. We obtain mean-field ground state phase diagram by variational method. In the regime where interspecies coupling is larger than intraspecies coupling, the system is found to be fully polarized and condensed at a finite momentum lying along the quantization axis. We characterize this phase by studying the excitation spectrum, the sound velocity, the quantum depletion of condensates, the shift of ground state...

Topics: Quantum Gases, Condensed Matter, Quantum Physics

Source: http://arxiv.org/abs/1701.03673

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4.0

Jun 30, 2018
06/18

by
Paul Skrzypczyk; Ralph Silva; Nicolas Brunner

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We give a simple and intuitive proof that the only states which are completely passive, i.e. those states from which work cannot be extracted even with infinitely many copies, are Gibbs states at positive temperatures. The proof makes use of the idea of virtual temperatures, i.e. the association of temperatures to pairs of energy levels (transitions). We show that (i) passive states are those where every transition is at a positive temperature, and (ii) completely passive states are those where...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1412.5485

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3.0

Jun 30, 2018
06/18

by
Thomas E. Skinner

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An exact general theory of heteronuclear decoupling is presented for spin-1/2 IS systems. RF irradiation applied to the I spins decouples the S spins by reversing the sign of antiphase magnetization. A one-to-one correspondence is demonstrated between the sign of $2S_yI_z$ and the sense of the S-spin coupling evolution, with magnetization $S_x$ refocused when $\int 2S_yI_z\,dt = 0$. The exact instantaneous coupling at any time during the decoupling sequence is readily obtained in terms of the...

Topics: Physics, Chemical Physics, Quantum Physics

Source: http://arxiv.org/abs/1403.6447

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6.0

Jun 28, 2018
06/18

by
Chris L. Lin; Carlos R. Ordonez

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We derive the relativistic thermodynamic scale equation using imaginary-time path integrals, with complex scalar field theory taken as a concrete example. We use Fujikawa's method to derive the scaling anomaly for this system using a matrix regulator. We make a general scaling argument to show how for anomalous systems, the $\beta$ function of the vacuum theory can be derived from measurement of macroscopic thermodynamic parameters.

Topics: Quantum Physics, Statistical Mechanics, Condensed Matter, High Energy Physics - Theory

Source: http://arxiv.org/abs/1508.05666

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6.0

Jun 29, 2018
06/18

by
Jeconias Rocha Guimarães

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On this paper I present a quantum representation based on linear momentum, which is independent of wave function. I derived one equation that relates external potential with linear momentum and other that allows calculate wave function through it. The first one is a non homogeneous first order differential equation and the second one demands uniquely to evaluate an integral. Throughout this paper, I solve two systems using this methodology in order to demonstrate its feasibility. Since it is...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1612.09114

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Jun 30, 2018
06/18

by
Zafar Ahmed; Shashin Pavaskar; Lakshmi Prakash

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We study scattering from potentials that rise monotonically on one side; this is generally avoided. We report that resonant states are absent in such potentials when they are smooth and single-piece having less than three real turning points (like in the cases of Morse oscillator, exponential and linear potentials). But when these potentials are made two-piece, resonances can occur. We further show that rising potentials next to a well/step/barrier are rich models of multiple resonances...

Topics: Quantum Physics, Mathematics, Mathematical Physics

Source: http://arxiv.org/abs/1408.0231

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10.0

Jun 29, 2018
06/18

by
Asutosh Kumar; Himadri Shekhar Dhar

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In multiparty quantum systems, the monogamy inequality proposes an upper bound on the distribution of bipartite quantum correlation between a single party and each of the remaining parties in the system, in terms of the amount of quantum correlation shared by that party with the rest of the system taken as a whole. However, it is well-known that not all quantum correlation measures universally satisfy the monogamy inequality. In this work, we aim at determining the non-trivial value by which...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1603.02957

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Jun 29, 2018
06/18

by
Bruno G. Taketani; Luke C. G. Govia; Frank K. Wilhelm

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Quantum walks are a promising framework that can be used to both understand and implement quantum information processing tasks. The quantum stochastic walk is a recently developed framework that combines the concept of a quantum walk with that of a classical random walk, through open system evolution of a quantum system. Quantum stochastic walks have been shown to have applications in as far reaching fields as artificial intelligence. However, there are significant constraints on the kind of...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1603.03699

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Jun 29, 2018
06/18

by
David Kribs; Comfort Mintah; Michael Nathanson; Rajesh Pereira

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We conduct the first detailed analysis in quantum information of recently derived operator relations from the study of quantum one-way local operations and classical communications (LOCC). We show how operator structures such as operator systems, operator algebras, and Hilbert C*-modules all naturally arise in this setting, and we make use of these structures to derive new results and new derivations of some established results in the study of LOCC. We also show that perfect distinguishability...

Topics: Quantum Physics, Operator Algebras, Mathematics

Source: http://arxiv.org/abs/1612.03796

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10.0

Jun 29, 2018
06/18

by
Simon Saunders

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The notion of objective probability or chance, as a physical trait of the world, has proved elusive; the identification of chances with actual frequencies does not succeed. An adequate theory of chance should explain not only the connection of chance with statistics, but with degrees of belief, and more broadly the entire phenomenology of (seemingly) chance events and their measurement. Branching structure in the decoherence-based many worlds theory provides an account of what chance is that...

Topics: Quantum Physics, History and Philosophy of Physics, Physics

Source: http://arxiv.org/abs/1609.04720

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Jun 30, 2018
06/18

by
O. V. Marchukov; D. V. Fedorov; A. S. Jensen; A. G. Volosniev; N. T. Zinner

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We investigate a two-dimensional system of with two values of the internal (spin) degree of freedom. It is confined by a deformed harmonic trap and subject to a Zeeman field, Rashba or Dresselhaus one-body spin-orbit couplings and two-body short range repulsion. We obtain self-consistent mean-field $N$-body solutions as functions of the interaction parameters. Single-particle Spectra and total energies are computed and compared to the results without interaction. We perform a statistical...

Topics: Quantum Gases, Quantum Physics, Condensed Matter

Source: http://arxiv.org/abs/1409.4206

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4.0

Jun 28, 2018
06/18

by
G. Edward Marti; Dan M. Stamper-Kurn

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In a spinor Bose-Einstein gas, the non-zero hyperfine spin of the gas becomes an accessible degree of freedom. At low temperature, such a gas shows both magnetic and superfluid order, and undergoes both density and spin dynamics. These lecture notes present a general overview of the properties of spinor Bose-Einstein gases. The notes are divided in five sections. In the first, we summarize basic properties of multi-component quantum fluids, focusing on the specific case of spinor Bose-Einstein...

Topics: Quantum Physics, Quantum Gases, Condensed Matter

Source: http://arxiv.org/abs/1511.01575