02.10.+t Quantum-Classical Transition

Absorbing state phase transition with competing quantum and classical fluctuations

Date: 
2016-01-27
Author(s): 

M. Marcuzzi, M. Buchhold, S. Diehl, and I. Lesanovsky

Reference: 

Physical Review Letters 116, 245701 (2016)

From classical to quantum criticality

Date: 
2014-06-11
Author(s): 

D. Podolsky, E. Shimshoni, P. Silvi, S. Montangero, T. Calarco, G. Morigi, S. Fishman

Reference: 

Phys. Rev. B 89, 214408 (2014)
http://dx.doi.org/10.1103/PhysRevB.89.214408

We study the crossover from classical to quantum phase transitions at zero temperature within the framework of

Violation of Bell inequalities in larger Hilbert spaces: robustness and challenges

Date: 
2016-01-08
Author(s): 

W. Weiss, G. Benenti, G. Casati, I. Guarneri, T. Calarco, M. Paternostro, S. Montangero

Reference: 

New J. Phys. 18 013021 (2016)
http://dx.doi.org/10.1088/1367-2630/18/1/013021

We explore the challenges posed by the violation of Bell-like inequalities by d-dimensional systems exposed to imperfect state-preparation and measurement settings. We address, in particular, the limit of high-dimensional systems, naturally arising when exploring the quantum-to-classical transition. We show that, although suitable Bell inequalities can be violated, in principle, for any dimension of given subsystems, it is in practice increasingly challenging to detect such violations, even if the system is prepared in a maximally entangled state.

Controlling the transport of an ion: Classical and quantum mechanical solutions

Date: 
2014-07-01
Author(s): 

H. A. Fürst, M. H. Goerz, U. G. Poschinger, M. Murphy, S. Montangero, T.
Calarco, F. Schmidt-Kaler, K. Singer, C. P. Koch

Reference: 

Journal reference: New J. Phys. 16, 075007 (2014)
DOI: 10.1088/1367-2630/16/7/075007

We investigate the performance of different control techniques for ion transport in state-of-the-art segmented miniaturized ion traps. We employ numerical optimization of classical trajectories and quantum wavepacket propagation as well as analytical solutions derived from invariant based inverse engineering and geometric optimal control.

From classical to quantum criticality

Date: 
2014-06-11
Author(s): 

D. Podolsky, E. Shimshoni, P. Silvi, S. Montangero, T. Calarco, G.
Morigi, S. Fishman

Reference: 

Journal reference: Phys. Rev. B 89, 214408 (2014)
DOI: 10.1103/PhysRevB.89.214408

We study the crossover from classical to quantum phase transitions at zero temperature within the framework of ϕ4 theory. The classical transition at zero temperature can be described by the Landau theory, turning into a quantum Ising transition with the addition of quantum fluctuations. We perform a calculation of the transition line in the regime where the quantum fluctuations are weak. The calculation is based on a renormalization group analysis of the crossover between classical and quantum transitions, and is well controlled even for space-time dimensionality D below 4.

Sympathetic cooling of a membrane oscillator in a hybrid mechanical-atomic system

Date: 
2014-11-24
Author(s): 

A. Jöckel, A. Faber, T. Kampschulte, M. Korppi, M. T. Rakher, and P. Treutlein

Reference: 

Nature Nanotechnology 10, 55-59 (2015).

Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to 90 times larger than that of the coolant atom. Here, we use ultracold atoms to sympathetically cool the vibrations of a Si3N4 nanomembrane, the mass of which exceeds that of the atomic ensemble by a factor of 1010.

Macroscopic Optomechanics from Displaced Single-Photon Entanglement

Date: 
2014-02-27 - 2014-05-12
Author(s): 

Pavel Sekatski, Markus Aspelmeyer, Nicolas Sangouard

Reference: 

Phys. Rev. Lett. 112, 080502 (2014)

Displaced single-photon entanglement is a simple form of optical entanglement, obtained by sending a photon on a beamsplitter and subsequently applying a displacement operation.

Heralded Single-Phonon Preparation, Storage, and Readout in Cavity Optomechanics

Date: 
2014-04-09 - 2014-05-09
Author(s): 

Christophe Galland, Nicolas Sangouard, Nicolas Piro, Nicolas Gisin, and Tobias J. Kippenberg

Reference: 

Physical Review Letters 112, 143602 – Published 9 April 2014

We show how to use the radiation pressure optomechanical coupling between a mechanical oscillator and an optical cavity field to generate in a heralded way a single quantum of mechanical motion (a Fock state). Starting with the oscillator close to its ground state, a laser pumping the upper motional sideband produces correlated photon-phonon pairs via optomechanical parametric down-conversion.

Detecting nonlocality of noisy multipartite states with the CHSH inequality

Date: 
2014-04-14
Author(s): 

Rafael Chaves, Antonio Acín, Leandro Aolita, Daniel Cavalcanti

Reference: 

Phys. Rev. A 89, 042106 (2014)

The Clauser-Horne-Shimony-Holt inequality was originally proposed as a Bell inequality to detect nonlocality in bipartite systems. However, it can also be used to certify the nonlocality of multipartite quantum states. We apply this to study the nonlocality of multipartite Greenberger-Horne-Zeilinger, W and graph states under local decoherence processes.

Unconventional superfluidity of fermions in Bose-Fermi mixtures

Date: 
2010-06-07
Reference: 

O. Dutta, M. Lewenstein
Phys. Rev. A 81, 063608 (2010)

We examine two dimensional mixture of single-component fermions and dipolar bosons. We calculate the self-enregies of the fermions in the normal state and the Cooper pair channel by including first order vertex correction to derive a modified Eliashberg equation. We predict appearance of superfluids with various non-standard pairing symmetries at experimentally feasible transition temperatures within the strong-coupling limit of the Eliashberg equation. Excitations in these superfluids are anyonic and follow non-Abelian statistics.

Syndicate content