Manipulation of the dynamics of many-body systems via quantum control methods

TL;DR

This paper explores how quantum control methods, specifically dynamical decoupling sequences, can manipulate the evolution of many-body quantum systems, transforming their dynamical behavior across different phases and integrability regimes.

Contribution

It demonstrates that tailored control sequences can convert chaotic systems into integrable ones and alter phase characteristics in quantum many-body models.

Findings

Control sequences can induce integrability in chaotic chains.

Control methods can change phase behavior from gapless to gapped.

Different time intervals in control sequences are crucial for manipulation.

Abstract

We investigate how dynamical decoupling methods may be used to manipulate the time evolution of quantum many-body systems. These methods consist of sequences of external control operations designed to induce a desired dynamics. The systems considered for the analysis are one-dimensional spin-1/2 models, which, according to the parameters of the Hamiltonian, may be in the integrable or non-integrable limits, and in the gapped or gapless phases. We show that an appropriate control sequence may lead a chaotic chain to evolve as an integrable chain and a system in the gapless phase to behave as a system in the gapped phase. A key ingredient for the control schemes developed here is the possibility to use, in the same sequence, different time intervals between control operations.