Spin-lattice relaxation with non-linear couplings: Comparison between Fermi's golden rule and extended dissipaton equation of motion

Fuente: arXiv
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Main Authors: Bi, Rui-Hao, Su, Yu, Wang, Yao, Sun, Lei, Dou, Wenjie
Format: Preprint
Published: 2024
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author Bi, Rui-Hao
Su, Yu
Wang, Yao
Sun, Lei
Dou, Wenjie
author_facet Bi, Rui-Hao
Su, Yu
Wang, Yao
Sun, Lei
Dou, Wenjie
contents Fermi's golden rule (FGR) offers an empirical framework for understanding the dynamics of spin-lattice relaxation in magnetic molecules, encompassing mechanisms like direct (one-phonon) and Raman (two-phonon) processes. These principles effectively model experimental longitudinal relaxation rates, denoted as $T_1^{-1}$. However, under scenarios of increased coupling strength and nonlinear spin-lattice interactions, FGR's applicability may diminish. This paper numerically evaluates the exact spin-lattice relaxation rate kernels, employing the extended dissipaton equation of motion (DEOM) formalism. Our calculations reveal that when quadratic spin-lattice coupling is considered, the rate kernels exhibit a free induction decay-like feature, and the damping rates depend on the interaction strength. We observe that the temperature dependence predicted by FGR significantly deviates from the exact results since FGR ignores the non-Markovian nature of spin-lattice relaxation. Our methods can be readily applied to other systems with nonlinear spin-lattice interactions and provide valuable insights into the temperature dependence of $T_1$ in molecular qubits.
format Preprint
id arxiv_https___arxiv_org_abs_2404_04803
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Spin-lattice relaxation with non-linear couplings: Comparison between Fermi's golden rule and extended dissipaton equation of motion
Bi, Rui-Hao
Su, Yu
Wang, Yao
Sun, Lei
Dou, Wenjie
Chemical Physics
Quantum Physics
Fermi's golden rule (FGR) offers an empirical framework for understanding the dynamics of spin-lattice relaxation in magnetic molecules, encompassing mechanisms like direct (one-phonon) and Raman (two-phonon) processes. These principles effectively model experimental longitudinal relaxation rates, denoted as $T_1^{-1}$. However, under scenarios of increased coupling strength and nonlinear spin-lattice interactions, FGR's applicability may diminish. This paper numerically evaluates the exact spin-lattice relaxation rate kernels, employing the extended dissipaton equation of motion (DEOM) formalism. Our calculations reveal that when quadratic spin-lattice coupling is considered, the rate kernels exhibit a free induction decay-like feature, and the damping rates depend on the interaction strength. We observe that the temperature dependence predicted by FGR significantly deviates from the exact results since FGR ignores the non-Markovian nature of spin-lattice relaxation. Our methods can be readily applied to other systems with nonlinear spin-lattice interactions and provide valuable insights into the temperature dependence of $T_1$ in molecular qubits.
title Spin-lattice relaxation with non-linear couplings: Comparison between Fermi's golden rule and extended dissipaton equation of motion
topic Chemical Physics
Quantum Physics
url https://arxiv.org/abs/2404.04803