Showing 2009 · quant-phShow all

20 papers · 2 filters

quant-ph2009★ 101 cited

Operator Space theory: a natural framework for Bell inequalities

M. Junge, C. Palazuelos, D. Perez-Garcia +2

In this letter we show that the field of Operator Space Theory provides a general and powerful mathematical framework for arbitrary Bell inequalities, in particular regarding the s…

quant-ph2009★ 16 cited

Full tomography from compatible measurements

J. Rehacek, Z. Hradil, Z. Bouchal +3

We put forward a reconstruction scheme prompted by the relation between a von Neumann measurement and the corresponding informationally complete measurement induced in a relevant r…

quant-ph2009★ 1 cited

An Extreme form of Superactivation for Quantum Zero-Error Capacities

Toby S. Cubitt, Graeme Smith

The zero-error capacity of a channel is the rate at which it can send information perfectly, with zero probability of error, and has long been studied in classical information theo…

quant-ph2009★ 19 cited

Mapping all classical spin models to a lattice gauge theory

G. De las Cuevas, W. Dür, H. J. Briegel +1

In our recent work [Phys. Rev. Lett. 102, 230502 (2009)] we showed that the partition function of all classical spin models, including all discrete standard statistical models and…

quant-ph2009★ 54 cited

Unbounded violations of bipartite Bell Inequalities via Operator Space theory

M. Junge, C. Palazuelos, D. Perez-Garcia +2

In this work we show that bipartite quantum states with local Hilbert space dimension n can violate a Bell inequality by a factor of order (up to a logarithmic factor) w…

quant-ph2009★ 11 cited

Angular performance measure for tighter uncertainty relations

Z. Hradil, J. Rehacek, A. B. Klimov +2

The uncertainty principle places a fundamental limit on the accuracy with which we can measure conjugate physical quantities. However, the fluctuations of these variables can be as…

quant-ph2009★ 42 cited

Temperature dependence of the magnetic Casimir-Polder interaction

H. Haakh, F. Intravaia, C. Henkel +4

We analyze the magnetic dipole contribution to atom-surface dispersion forces. Unlike its electrical counterpart, it involves small transition frequencies that are comparable to th…

quant-ph2009★ 31 cited

Topological color codes on Union Jack lattices: A stable implementation of the whole Clifford group

Helmut G. Katzgraber, H. Bombin, Ruben S. Andrist +1

We study the error threshold of topological color codes on Union Jack lattices that allow for the full implementation of the whole Clifford group of quantum gates. After mapping th…

quant-ph2009★ 114 cited

A quantum version of Wielandt's inequality

M. Sanz, D. Perez-Garcia, M. M. Wolf +1

In this paper, Wielandt's inequality for classical channels is extended to quantum channels. That is, an upper bound to the number of times a channel must be applied, so that it ma…

quant-ph2009★ 20 cited

Non-negative Wigner functions for orbital angular momentum states

I. Rigas, L. L. Sanchez-Soto, A. B. Klimov +2

The Wigner function of a pure continuous-variable quantum state is non-negative if and only if the state is Gaussian. Here we show that for the canonical pair angle and angular mom…

quant-ph2009★ 75 cited

A canonical form for Projected Entangled Pair States and applications

D. Perez-Garcia, M. Sanz, C. E. Gonzalez-Guillen +2

We show that two different tensors defining the same translational invariant injective Projected Entangled Pair State (PEPS) in a square lattice must be the same up to a trivial ga…

quant-ph2009★ 7 cited

Depolarization for quantum channels with higher symmetries

A. B. Klimov, L. L. Sanchez-Soto

The depolarization channel is usually modelled as a quantum operation that destroys all input information, replacing it by a completely chaotic state. For qubits this has a quite i…

quant-ph2009★ 34 cited

Discrete coherent and squeezed states of many-qudit systems

A. B. Klimov, C. Munoz, L. L. Sanchez-Soto

We consider the phase space for a system of identical qudits (each one of dimension , with a primer number) as a grid of points and use the finite f…

quant-ph2009★ 19 cited

Robust stationary entanglement of two coupled qubits in independent environments

M. Scala, R. Migliore, A. Messina +1

The dissipative dynamics of two interacting qubits coupled to independent reservoirs at nonzero temperatures is investigated, paying special attention to the entanglement evolution…

quant-ph2009★ 3 cited

Self-Correcting Quantum Computers

H. Bombin, R. W. Chhajlany, M. Horodecki +1

Is the notion of a quantum computer resilient to thermal noise unphysical? We address this question from a constructive perspective and show that local quantum Hamiltonian models p…

quant-ph2009★ 50 cited

Superactivation of the Asymptotic Zero-Error Classical Capacity of a Quantum Channel

Toby S. Cubitt, Jianxin Chen, Aram W. Harrow

The zero-error classical capacity of a quantum channel is the asymptotic rate at which it can be used to send classical bits perfectly, so that they can be decoded with zero probab…

quant-ph2009★ 202 cited

Measurements incompatible in Quantum Theory cannot be measured jointly in any other local theory

Michael M. Wolf, David Perez-Garcia, Carlos Fernandez

It is well known that jointly measurable observables cannot lead to a violation of any Bell inequality - independent of the state and the measurements chosen at the other site. In…

quant-ph2009★ 145 cited

The geometric measure of entanglement for symmetric states

R. Hübener, M. Kleinmann, T. -C. Wei +2

Is the closest product state to a symmetric entangled multiparticle state also symmetric? This question has appeared in the recent literature concerning the geometric measure of en…

quant-ph2009★ 13 cited

Causation, Measurement Relevance and No-conspiracy in EPR

Iñaki San Pedro

In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EP…

quant-ph2009★ 43 cited

Assessing dimensions from evolution

Michael M. Wolf, David Perez-Garcia

Using tools from classical signal processing, we show how to determine the dimensionality of a quantum system as well as the effective size of the environment's memory from observa…