ICTS:30895

Video URL

Dynamics of Noisy (+ non-Hermitian) quantum systems

Dynamics of Noisy (+ non-Hermitian) quantum systems

(2025). Dynamics of Noisy (+ non-Hermitian) quantum systems. SciVideos. https://youtu.be/FIgiuHf28O0

Dynamics of Noisy (+ non-Hermitian) quantum systems. SciVideos, Feb. 03, 2025, https://youtu.be/FIgiuHf28O0 

          @misc{ scivideos_ICTS:30895,
            doi = {},
            url = {https://youtu.be/FIgiuHf28O0},
            author = {},
            keywords = {},
            language = {en},
            title = {Dynamics of Noisy (+ non-Hermitian) quantum systems},
            publisher = {},
            year = {2025},
            month = {feb},
            note = {ICTS:30895 see, \url{https://scivideos.org/index.php/icts-tifr/30895}}
          }
Aurelia Chenu
Talk numberICTS:30895
Source RepositoryICTS-TIFR
Collection

Abstract

Quantum experiments are performed in noisy platforms. In NISQ devices, realistic setups can be described by open systems or noisy Hamiltonians. Using this setup, we explore a number of dynamical schemes and control techniques. First, starting from a generic noisy Hamiltonian, I will show how noise can help simulate long-range and many-body interaction in a quantum platform [1]. Second, in the setup of shortcut to adiabaticity extended to open quantum systems, we adapt our noisy Hamiltonian to control the thermalization of a harmonic oscillator [2] and generate a squeezed thermal state [3] in arbitrary time. 

Third, adding non-Hermiticity in the picture [3], I will show how noise allows for a rich control of the dynamics, and induced a new phase in which the lossy state becomes stable. More generally, we characterize the quantum dynamics generated by a non-Hermitian Hamiltonian subject to stochastic perturbations in its anti-Hermitian part, describing fluctuating gains and losses. 

Finally, I will briefly show results where we do not look at the noise-averaged density matrix but at an observable introduced as the stochastic operator variance (SOV), which characterizes the deviations of any operator from the noise-averaged operator in a stochastic evolution governed by the Hamiltonian.  Surprisingly, we find that the evolution of the noise-averaged variance relates to an out-of-time-order correlator (OTOC), which connects fluctuations of the system with scrambling, and thus allows computing the Lyapunov exponent.

[1] A. Chenu, M. Beau, J. Cao, and A. del Campo. Phys. Rev. Lett. 118:140403 (2017)
[2] L. Dupays, I. L. Egusquiza, A. del Campo,  and A. Chenu. Superadiabatic thermalization of a quantum oscillator by engineered dephasing, Phys. Rev. Res. 2:033178 (2020)
[3] L. Dupays and A. Chenu. Dynamical engineering of squeezed thermal state, Quantum 5:449 (2021)
[4] P. Martinez-Azcona, A.Kundu, A. Saxena, A. del Campo, and A. Chenu, ArXiv 2407.07746 
[5] P. Martinez-Azcona, A.Kundu, A. del Campo, and A. Chenu, Phys. Rev. Lett. 131:16202 (2023).