Rate Function Modelling of Quantum Many-Body Adiabaticity

Fuente: arXiv
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Autores principales: Mishra, Vibhu, Manmana, Salvatore, Kehrein, Stefan
Formato: Preprint
Publicado: 2024
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author Mishra, Vibhu
Manmana, Salvatore
Kehrein, Stefan
author_facet Mishra, Vibhu
Manmana, Salvatore
Kehrein, Stefan
contents The quantum adiabatic theorem is a fundamental result in quantum mechanics, with a multitude of applications, both theoretical and practical. Here, we investigate the dynamics of adiabatic processes for quantum many-body systems %in detail by analysing the properties of observable-free, intensive quantities. In particular, we study the adiabatic rate function $f(T, Δλ)$ in dependence of the ramp time $T$, which gives us a complete characterization of the many-body adiabatic fidelity as a function of $T$ and the strength of the parameter displacement $Δλ$. $f(T, Δλ)$ quantifies the deviation from adiabaticity for a given process and therefore allows us to control and define the notion of adiabaticity in many-body systems. First we study $f(T, Δλ)$ for the 1D transverse field Ising model and the Luttinger liquid, both of which are quadratic systems and therefore allow us to look at the thermodynamic limit. For ramps across gapped phases, we relate $f(T, Δλ)$ to the transition probability of the system and for ramps across a gapless point, or gapless phase we relate it to the excitation density of the relevant quasiparticles. Then we investigate the XXZ model which allows us to see the qualitative features that survive when interactions are turned on. Several key results in the literature regarding the interplay of the thermodynamic and the adiabatic limit are obtained as inferences from the properties of $f(T, Δλ)$ in the large $T$ limit.
format Preprint
id arxiv_https___arxiv_org_abs_2402_17415
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Rate Function Modelling of Quantum Many-Body Adiabaticity
Mishra, Vibhu
Manmana, Salvatore
Kehrein, Stefan
Quantum Physics
Other Condensed Matter
The quantum adiabatic theorem is a fundamental result in quantum mechanics, with a multitude of applications, both theoretical and practical. Here, we investigate the dynamics of adiabatic processes for quantum many-body systems %in detail by analysing the properties of observable-free, intensive quantities. In particular, we study the adiabatic rate function $f(T, Δλ)$ in dependence of the ramp time $T$, which gives us a complete characterization of the many-body adiabatic fidelity as a function of $T$ and the strength of the parameter displacement $Δλ$. $f(T, Δλ)$ quantifies the deviation from adiabaticity for a given process and therefore allows us to control and define the notion of adiabaticity in many-body systems. First we study $f(T, Δλ)$ for the 1D transverse field Ising model and the Luttinger liquid, both of which are quadratic systems and therefore allow us to look at the thermodynamic limit. For ramps across gapped phases, we relate $f(T, Δλ)$ to the transition probability of the system and for ramps across a gapless point, or gapless phase we relate it to the excitation density of the relevant quasiparticles. Then we investigate the XXZ model which allows us to see the qualitative features that survive when interactions are turned on. Several key results in the literature regarding the interplay of the thermodynamic and the adiabatic limit are obtained as inferences from the properties of $f(T, Δλ)$ in the large $T$ limit.
title Rate Function Modelling of Quantum Many-Body Adiabaticity
topic Quantum Physics
Other Condensed Matter
url https://arxiv.org/abs/2402.17415