Unification of quantum Zeno-anti Zeno effects and parity-time symmetry breaking transitions

Abstract

The decay of any unstable quantum state can be inhibited or enhanced by carefully tailored measurements, known as the quantum Zeno effect (QZE) or anti-Zeno effect (QAZE). To date, studies of QZE (QAZE) transitions have since expanded to various system-environment coupling, in which the time evolution can be suppressed (enhanced) not only by projective measurement but also through dissipation processes. However, a general criterion, which could extend to arbitrary dissipation strength and periodicity, is still lacking. In this letter, we show a general framework to unify QZE-QAZE effects and parity-time (PT) symmetry breaking transitions, in which the dissipative Hamiltonian associated to the measurement effect is mapped onto a PT-symmetric non- Hermitian Hamiltonian, thus applying the PT symmetry transitions to distinguish QZE (QAZE) and their crossover behavior. As a concrete example, we show that, in a two-level system periodically coupled to a dissipative environment, QZE starts at an exceptional point (EP), which separates the PT-symmetric (PTS) phase and PT-symmetry broken (PTB) phase, and ends at the resonance point (RP) of the maximum PT-symmetry breaking; while QAZE extends the rest of PTB phase and remains the whole PTS phase. Such findings reveal a hidden relation between QZE-QAZE and PTS-PTB phases in non-Hermitian quantum dynamics.

References in corpus (9)

• The physics of exceptional points
• Reversing the Pump-Dependence of a Laser at an Exceptional Point
• Observation of parity-time symmetry breaking in a single spin system
• PT spectroscopy of the Rabi problem
• Quantum Zeno effect appears in stages
• Incoherent qubit control using the quantum Zeno effect
• Quantum Zeno effects across a parity-time symmetry breaking transition in atomic momentum space
• Generalized relation between pulsed and continuous measurements in the quantum Zeno effect
• Quantum Zeno and anti-Zeno effects in open quantum systems

Cited by in corpus (6)

• Decoherence Induced Exceptional Points in a Dissipative Superconducting Qubit
• Observation of $\mathcal{P}\mathcal{T}$-symmetric quantum coherence in a single ion system
• Accelerating relaxation through Liouvillian exceptional point
• Timelessness strictly inside the Quantum Realm
• Simulating open quantum systems with giant atoms
• Many-body Liouvillian dynamics with a non-Hermitian tensor-network kernel polynomial algorithm