Información del autor
Autor Relaño Pérez, Armando |
Documentos disponibles escritos por este autor (48)
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Relaño Pérez, Armando ; Retamosa Granado, Joaquín ; Faleiro, E. ; Molina, R. A. ; Zuker, A. P. | American Physical Society | 2006-02It was recently pointed out that the spectral fluctuations of quantum systems are formally analogous to discrete time series, and therefore their structure can be characterized by the power spectrum of the signal. Moreover, it is found that the [...]texto impreso
Relaño Pérez, Armando ; Molina, R. A. ; Retamosa Granado, Joaquín | American Physical Society | 2004-07We show that the spectral fluctuations of the two-body random ensemble exhibit 1/f noise. This result supports a recent conjecture stating that chaotic quantum systems are characterized by 1/f noise in their energy level fluctuations. After suit[...]texto impreso
Relaño Pérez, Armando ; Gómez Gómez, José María ; Retamosa Granado, Joaquín ; Faleiro, E. ; Salasnich, L. ; Vranicar, M. ; Robnik, M. | American Physical Society | 2005-03-04The power law 1/ƒ^(?) in the power spectrum characterizes the fluctuating observables of many complex natural systems. Considering the energy levels of a quantum system as a discrete time series where the energy plays the role of time, the level[...]texto impreso
Bastarrachea Magnani A.; R, M. A. ; Relaño Pérez, Armando ; Lerma Hernández, S. ; López del Carpio, B. ; Chávez Carlos, J. ; Hirsch, J. G. | IOP publishing ltd | 2017-04-07Adiabatic invariants for the non-integrable Dicke model are introduced. They are shown to provide approximate second integrals of motion in the energy region where the system exhibits a regular dynamics. This low-energy region, present for any s[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Dukelsky, J. ; Arias, J. M. | American Institute of Physics (AIP) | 2013The Bose-Hubbard model coupled to a Feshbach resonance is studied. Quantum phase transitions are analyzed within a beyond mean field framework in order to get finite size corrections to the simple mean field approach. Analytical results for the [...]texto impreso
Gómez, J. M. G. ; Faleiro, E. ; Molina, R. A. ; Muñoz, L. ; Relaño Pérez, Armando | World Scientific Publishing Company | 2005-03Many complex systems in nature and in human society exhibit time fluctuations characterized by a power spectrum S(f) which is a power function of the frequency f . Examples with this behavior are the Sun spot activity, the human heartbeat, the D[...]texto impreso
It has been shown that the spectral fluctuations of different quantum systems are characterized by 1/ƒ^(?) noise, with 1texto impreso
Muñoz, Laura ; Fernández Ramírez, César ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | IOP publishing ltd | 2012In the last decade quantum chaos has become a well established discipline with outreach to different fields, from condensed-matter to nuclear physics. The most important signature of quantum chaos is the statistical analysis of the energy spectr[...]texto impreso
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Pérez Fernández, P. ; Relaño Pérez, Armando ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Institute of Physics (AIP) | 2010In this work we explore the relationship between an excited state quantum phase transition (ESQPT) and the phenomenon of quantum decoherence. For this purpose, we study how the decoherence is affected by the presence of a continuous ESQPT in the[...]texto impreso
Relaño Pérez, Armando ; Retamosa Granado, Joaquín ; Faleiro, E. ; Gómez Gómez, José María | American Physical Society | 2005-12The existence of a formal analogy between quantum energy spectra and discrete time series has been recently pointed out. When the energy level fluctuations are described by means of the ?_(n) statistic, it is found that chaotic quantum systems a[...]texto impreso
García Ramos, J. E. ; Arias, J. M. ; Cejnar, P. ; Dukelsky, J. ; Pérez Fernández, P. ; Relaño Pérez, Armando | American Institute of Physics (AIP) | 2012We study the similarities and differences between the phenomena of Quantum Decoherence and Quantum Quench in presence of an Excited State Quantum Phase Transition (ESQPT). We analyze, on one hand, the decoherence induced on a single qubit by the[...]texto impreso
Relaño Pérez, Armando ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. ; Pérez Fernández, P. | American Physical Society | 2008-12We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the environ[...]texto impreso
García Ramos, J. E. ; Arias, J. M. ; Dukelsky, J. ; Pérez Fernández, P. ; Relaño Pérez, Armando | American Institute of Physics (AIP) | 2009We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the environ[...]texto impreso
Relaño Pérez, Armando ; Pérez Fernández, P. ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Physical Society | 2009-09The decoherence induced on a single qubit by its interaction with the environment is studied. The environment is modeled as a scalar two-level boson system that can go through either first-order or continuous-excited-state quantum phase transiti[...]texto impreso
The decoherence interpretation of quantum measurements is applied to Wigner's-friend experiments. A framework in which all the experimental outcomes arise from unitary evolutions is proposed. Within it, a measurement is not completed until an un[...]texto impreso
Decoherence induced by an interacting spin environment in the transition from integrability to chaos
We investigate the decoherence properties of a central system composed of two spins 1/2 in contact with a spin bath. The dynamical regime of the bath ranges from a fully integrable limit to complete chaoticity. We show that the dynamical regime [...]texto impreso
Theoretical expressions for the distribution of the ratio of consecutive level spacings for quantum systems with transiting dynamics remain unknown. We propose a family of one-parameter distributions P(r) P(r; beta), where beta is an element of [...]texto impreso
We study nonequilibrium processes in an isolated quantum system-the Dicke model-focusing on the role played by the transition from integrability to chaos and the presence of excited-state quantum phase transitions. We show that both diagonal and[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Arias, J. M. ; Cejnar, P. ; Dukelsky, J. ; García Ramos, J. E. | American Physical Society | 2011-04-15We study the critical behavior of excited states and its relation to order and chaos in the Jaynes-Cummings and Dicke models of quantum optics. We show that both models exhibit a chain of excited-state quantum phase transitions demarcating the u[...]texto impreso
Puebla, Ricardo ; Relaño Pérez, Armando ; Retamosa Granado, Joaquín | American Physical Society | 2013-02-19We study the phase diagram of the Dicke model in terms of the excitation energy and the radiation-matter coupling constant lambda. Below a certain critical value lambda(c), all the energy levels have a well-defined parity. For lambda > lambda(c[...]texto impreso
Pérez Fernández, P. ; Relaño Pérez, Armando ; Cejnar, P. ; Arias, J. M. ; Dukelsky, J. ; García Ramos, J. E. | American Institute of Physics (AIP) | 2012In this contribution, the critical behavior of excited state quantum phase transitions (ESQPT's) and its relation to order and chaos in the Dicke model are studied. This model is non-integrable. For comparison, the same problem is studied for th[...]texto impreso
We study the integrability of the two-spin elliptic Gaudin model for arbitrary values of the Hamiltonian parameters. The limit of a very large spin coupled to a small one is well described by a semiclassical approximation with just one degree of[...]texto impreso
We present a theory that accurately describes the counting of excited states of a noninteracting fermionic gas. At high excitation energies the results reproduce Bethe's theory. At low energies oscillatory corrections to the many-body density of[...]texto impreso
We study the thermodynamics of the full version of the Dicke model, including all the possible values of the total angular momentum j, with bothmicrocanonical and canonical ensembles. We focus on both the excited-state quantum phase transition, [...]