Local dynamics and thermal activation in the transverse-field Ising chain

Abstract

There has been considerable recent progress in identifying candidate materials for the transversefield Ising chain (TFIC), a paradigmatic model for quantum criticality. Here, we study the local spin dynamical structure factor of different spin components in the quantum disordered region of the TFIC. We show that the low-frequency local dynamics of the spins in the Ising-and transverse-field directions have strikingly distinctive temperature dependencies. This leads to the thermal-activation gap for the secular term of the nuclear magnetic resonance (NMR) 1/T 2 relaxation rate to be half of that for the 1/T1 relaxation rate. Our findings reveal a new surprise in the nonzero-temperature dynamics of the venerable TFIC model and uncover a means to evince the material realization of the TFIC universality.

Magnetic excitations in the one-dimensional Heisenberg–Ising model with external fields and their experimental realizations

“…Substantial progresses are made with a series of theoretical work [28,30,32,44,45] which clearly identify proper parameters to realize those physics in corresponding materials. Meanwhile, experiments are carried out and unambiguously realize for the first time the longdesired physics in corresponding quasi-1D materials [46][47][48][49][50][51][52][53][54][55].…”

Magnetic excitations in the one-dimensional Heisenberg-Ising model with external fields and their experimental realizations

“…Substantial progresses are made with a series of theoretical work [28,30,32,44,45] which clearly identify proper parameters to realize those physics in corresponding materials. Meanwhile, experiments are carried out and unambiguously realize for the first time the long-desired physics in corresponding quasi-1D materials [46][47][48][49][50][51][52][53][54][55].…”