2024/09/09 by Weihua Xie, Xie, Weihua, Michael Kolodrubetz +3
Physics and Astronomy · #FOS: Physical sciences #Quantum Mechanics and Non-Hermitian Physics #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Statistical Mechanics (cond-mat.stat-mech) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2409.06113
openalex publication_date 2024/09/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Non-Hermitian quantum dynamics lie in an intermediate regime between unitary Hamiltonian dynamics and trace-preserving non-unitary open quantum system dynamics. Given differences in the noise tolerance of unitary and non-unitary dynamics, it is interesting to consider implementing non-Hermitian dynamics on a noisy quantum computer. In this paper, we do so for a non-Hermitian Ising Floquet model whose many-body dynamics gives rise to persistent temporal oscillations, a form of time crystallinity. In the simplest two qubit case that we consider, there is an infinitely long-lived periodic steady state at certain fine-tuned points. These oscillations remain reasonably long-lived over a range of parameters in the ideal non-Hermitean dynamics and for the levels of noise and imperfection expected of modern day quantum devices. Using a generalized Floquet analysis, we show that infinitely long-lived oscillations are generically lost for arbitrarily weak values of common types of noise and compute corresponding damping rate. We perform simulations using IBM's Qiskit platform to confirm our findings; however, experiments on a real device (ibmq-lima) do not show remnants of these oscillations.