| Records |
Author  |
Perez, A. |
| Title |
Asymptotic properties of the Dirac quantum cellular automaton |
Type |
Journal Article |
| Year |
2016 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys. Rev. A |
| Volume |
93 |
Issue |
1 |
Pages |
012328 - 10pp |
| Keywords |
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| Abstract |
We show that the Dirac quantum cellular automaton [A. Bisio, G. M. D'Ariano, and A. Tosini, Ann. Phys. (N. Y.) 354, 244 (2015)] shares many properties in common with the discrete-time quantum walk. These similarities can be exploited to study the automaton as a unitary process that takes place at regular time steps on a one-dimensional lattice, in the spirit of general quantum cellular automata. In this way, it becomes an alternative to the quantum walk, with a dispersion relation that can be controlled by a parameter that plays a similar role to the coin angle in the quantum walk. The Dirac Hamiltonian is recovered under a suitable limit. We provide two independent analytical approximations to the long-term probability distribution. It is shown that, starting from localized conditions, the asymptotic value of the entropy of entanglement between internal and motional degrees of freedom overcomes the known limit that is approached by the quantum walk for the same initial conditions and is similar to the ones achieved by highly localized states of the Dirac equation. |
| Address |
[Perez, A.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, E-46100 Valencia, Spain |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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| Language |
English |
Summary Language |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1050-2947 |
ISBN |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000368291600005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
2520 |
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| Author |
Martone, G.I.; Larre, P.E.; Fabbri, A.; Pavloff, N. |
| Title |
Momentum distribution and coherence of a weakly interacting Bose gas after a quench |
Type |
Journal Article |
| Year |
2018 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys. Rev. A |
| Volume |
98 |
Issue |
6 |
Pages |
063617 - 21pp |
| Keywords |
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| Abstract |
We consider a weakly interacting uniform atomic Bose gas with a time-dependent nonlinear coupling constant. By developing a suitable Bogoliubov treatment we investigate the time evolution of several observables, including the momentum distribution, the degree of coherence in the system, and their dependence on dimensionality and temperature. We rigorously prove that the low-momentum Bogoliubov modes remain frozen during the whole evolution, while the high-momentum ones adiabatically follow the change in time of the interaction strength. At intermediate momenta we point out the occurrence of oscillations, which are analogous to Sakharov oscillations. We identify two wide classes of time-dependent behaviors of the coupling for which an exact solution of the problem can be found, allowing for an analytic computation of all the relevant observables. A special emphasis is put on the study of the coherence property of the system in one spatial dimension. We show that the system exhibits a smooth “light-cone effect,” with typically no prethermalization. |
| Address |
[Martone, Giovanni I.; Pavloff, Nicolas] Univ Paris Saclay, Univ Paris Sud, CNRS, LPTMS,UMR 8626, F-91405 Orsay, France |
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| Publisher |
Amer Physical Soc |
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| Language |
English |
Summary Language |
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Edition |
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| ISSN |
2469-9926 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000452949900009 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3841 |
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| Author |
Marquez-Martin, I.; Di Molfetta, G.; Perez, A. |
| Title |
Fermion confinement via quantum walks in (2+1)-dimensional and (3+1)-dimensional space-time |
Type |
Journal Article |
| Year |
2017 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys. Rev. A |
| Volume |
95 |
Issue |
4 |
Pages |
042112 - 5pp |
| Keywords |
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| Abstract |
We analyze the properties of a two-and three-dimensional quantum walk that are inspired by the idea of a brane-world model put forward by Rubakov and Shaposhnikov [Phys. Lett. B 125, 136 (1983)]. In that model, particles are dynamically confined on the brane due to the interaction with a scalar field. We translated this model into an alternate quantum walk with a coin that depends on the external field, with a dependence which mimics a domain wall solution. As in the original model, fermions (in our case, the walker) become localized in one of the dimensions, not from the action of a random noise on the lattice (as in the case of Anderson localization) but from a regular dependence in space. On the other hand, the resulting quantum walk can move freely along the “ordinary” dimensions. |
| Address |
[Marquez-Martin, I.; Di Molfetta, G.; Perez, A.] Univ Valencia, CSIC, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: giuseppe.dimolfetta@lif.univ-mrs.fr |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2469-9926 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000399931500006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3102 |
| Permanent link to this record |
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| Author |
Marquez-Martin, I.; Arnault, P.; Di Molfetta, G.; Perez, A. |
| Title |
Electromagnetic lattice gauge invariance in two-dimensional discrete-time quantum walks |
Type |
Journal Article |
| Year |
2018 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys. Rev. A |
| Volume |
98 |
Issue |
3 |
Pages |
032333 - 8pp |
| Keywords |
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| Abstract |
Gauge invariance is one of the more important concepts in physics. We discuss this concept in connection with the unitary evolution of discrete-time quantum walks in one and two spatial dimensions, when they include the interaction with synthetic, external electromagnetic fields. One introduces this interaction as additional phases that play the role of gauge fields. Here, we present a way to incorporate those phases, which differs from previous works. Our proposal allows the discrete derivatives, that appear under a gauge transformation, to treat time and space on the same footing, in a way which is similar to standard lattice gauge theories. By considering two steps of the evolution, we define a density current which is gauge invariant and conserved. In the continuum limit, the dynamics of the particle, under a suitable choice of the parameters, becomes the Dirac equation and the conserved current satisfies the corresponding conservation equation. |
| Address |
[Marquez-Martin, Ivan; Arnault, Pablo; Di Molfetta, Giuseppe; Perez, Armando] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: ivan.marquez@uv.es; |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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| Language |
English |
Summary Language |
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Abbreviated Series Title |
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Edition |
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| ISSN |
2469-9926 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000446163200006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3750 |
| Permanent link to this record |
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| Author |
Hinarejos, M.; Di Franco, C.; Romanelli, A.; Perez, A. |
| Title |
Chirality asymptotic behavior and non-Markovianity in quantum walks on a line |
Type |
Journal Article |
| Year |
2014 |
Publication |
Physical Review A |
Abbreviated Journal |
Phys. Rev. A |
| Volume |
89 |
Issue |
5 |
Pages |
052330 - 7pp |
| Keywords |
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| Abstract |
We investigate the time evolution of the chirality reduced density matrix for a discrete-time quantum walk on a one-dimensional lattice. The matrix is obtained by tracing out the spatial degree of freedom. We analyze the standard case, without decoherence, and the situation in which decoherence appears in the form of broken links in the lattice. By examining the trace distance for possible pairs of initial states as a function of time, we conclude that the evolution of the reduced density matrix is non-Markovian, in the sense defined by Breuer, Laine, and Piilo [Phys. Rev. Lett. 103, 210401 (2009)]. As the level of noise increases, the dynamics approaches a Markovian process. The highest non-Markovianity corresponds to the case without decoherence. The reduced density matrix tends always to a well-defined limit that we calculate, but only in the decoherence-free case is this limit nontrivial. |
| Address |
[Hinarejos, Margarida; Perez, Armando] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1050-2947 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000336751300003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1807 |
| Permanent link to this record |
