arXiv subjects

Camilo Moreno

Publications and source records attributed to Camilo Moreno.

4 recordsLinked to original sources

arXiv2024

Beyond the ensemble paradigm in low dimensional quantum gravity: Schwarzian density, quantum chaos and wormhole contributions

Based on periodic orbit theory we address the individual-system versus ensemble interpretation of quantum gravity from a quantum chaos perspective. To this end we show that the spectrum of geodesic motion on high-dimensional hyperbolic manifolds, described by the Selberg trace formula, displays a Schwarzian ($\sinh 2\pi\sqrt{E}$) mean level density. Due to its chaotic classical limit, this quantum system also shows all universal signatures of quantum chaos. These two properties imply a possible duality to Jackiw-Teitelboim-type quantum gravity at the level of a single system instead of an ensemble of systems like matrix theories and SYK models. Beyond the universal regime we show how the full wormhole geometry on the gravity side emerges from the discreteness of the set of periodic orbits. Thereby, we take initial steps towards a duality between gravitational and mesoscopic chaotic quantum systems through the topological, respectively, periodic orbit expansions of their correlators.

hep-th↗

arXiv2020

Position representation of single-mode Gaussian channels beyond the Gaussian functional form

We study one-mode Gaussian quantum channels in continuous-variable systems by performing a black-box characterization using complete positivity and trace preserving conditions, and report the existence of two subsets that do not have a functional Gaussian form. Our study covers as particular limit the case of singular channels, thus connecting our results with their known classification scheme based on canonical forms. Our full characterization of Gaussian channels without Gaussian functional form is completed by showing how Gaussian states are transformed under these operations, and by deriving the conditions for the existence of master equations for the non-singular cases. We show that although every functional form can be found in the vicinity of the identity, one of them does not parametrize unitary channels.

quant-ph↗

arXiv2020

Interplay between coherent and incoherent decay processes in chaotic systems: the role of quantum interference

The population decay due to a small opening in an otherwise closed cavity supporting chaotic classical dynamics displays a quantum correction on top of the classical exponential form, a pure manifestation of quantum coherence that acquires a universal form and can be explained by path interference. Being coherent, such enhancement is prone to decoherence effects due to the coupling of the system to an external environment. We study this interplay between incoherent and coherent quantum corrections to decay by evaluating, within a Caldeira-Legget scenario, off-diagonal contributions to the decoherence functional coming from pairs of correlated classical paths in the time regime where dissipative effects are neglected and decoherence does not affect the classical dynamics, but quantum interference must be accounted for. We find that the competing effects of interference and decoherence lead to a universal non-monotonous form for the survival probability depending only on the universality class, coupling strength, and macroscopic parameters of the cavity.

quant-ph↗

arXiv2019

Strong Coupling and non-Markovian Effects in the Statistical Notion of Temperature

We investigate the emergence of temperature $T$ in the system-plus-reservoir paradigm starting from the fundamental microcanonical scenario at total fixed energy $E$ where, contrary to the canonical approach, $T=T(E)$ is not a control parameter but a derived auxiliary concept. As shown by Schwinger for the regime of weak coupling $γ$ between subsystems, $T(E)$ emerges from the saddle-point analysis leading to the ensemble equivalence up to corrections ${\cal O}(1/\sqrt{N})$ in the number of particles $N$ that defines the thermodynamic limit. By extending these ideas for finite $γ$, while keeping $N\to \infty$, we provide a consistent generalization of temperature $T(E,γ)$ in strongly coupled systems and we illustrate its main features for the specific model of Quantum Brownian Motion where it leads to consistent microcanonical thermodynamics. Interestingly, while this $T(E,γ)$ is a monotonically increasing function of the total energy $E$, its dependence with $γ$ is a purely quantum effect notably visible near the ground state energy, and for large energies differs for Markovian and non-Markovian regimes.

quant-ph↗