Chaotic dynamics of two 1/2 spin-qubit system in the optical cavity

TL;DR

This paper investigates the chaotic behavior of a two spin-1/2 qubit system in an optical cavity, revealing how nonlinearity and recoil effects induce chaos and irreversibility, complicating quantum state control.

Contribution

It demonstrates that chaos arises in the two-spin qubit system due to recoil and center-of-mass motion, even at zero detuning, highlighting challenges in quantum control.

Findings

Chaotic dynamics occur due to recoil effects.

Chaos leads to irreversible transition to mixed states.

Chaos appears even at zero detuning.

Abstract

Spin systems are one of the most promising candidates for quantum computation. At the same time control of a system's quantum state during time evolution is one of the actual problems. It is usually considered that to hold well-known resonance condition in magnetic resonance is sufficient to control spin system. But because of nonlinearity of the system, obstructions of control of system's quantum state may emerge. In particular quantum dynamics of two 1/2 spin-qubit system in the optical cavity is studied in this work. The problem under study is a generalization of paradigmatic model for Cavity Quantum Electrodynamics of James-Cummings model in case of interacting spins. In this work it is shown that dynamics is chaotic when taking into account center-of-mass motion of the qubit and recoil effect. And besides even in case of zero detuning chaotic dynamics emerges in the system. It is also shown in this work that because of the chaotic dynamics the system execute irreversible transition from pure quantum-mechanical state to mixed one. Irreversibility in its turn is an obstacle for controlling state of quantum-mechanical system.