Floquet Engineering of Quantum Scars by Krishnendu Sengupta

Explore the fascinating world of quantum scars and their Floquet engineering in this 36-minute conference talk. Delve into the Eigenstate Thermalization Hypothesis and its violations, examining both classical and quantum scars in many-body Hamiltonians. Learn about the dipole model and its representation in terms of Ising spins, and discover how periodic driving and Magnus expansion can be applied to study quantum dynamics. Investigate the effects of noise on these systems, including random drive periods and their impact on coherent oscillations. Gain insights into the phase diagram of periodically driven Rydberg chains and the analytical predictions for coherent dynamics under random drive conditions. Conclude with a comprehensive overview of the field and participate in a Q&A session to deepen your understanding of this cutting-edge research in quantum physics.

Floquet engineering of quantum scars
Outline
Eigenstate Thermalization Hypothesis
Violation of ETH
Classical and Quantum Scars
Scars in Quantum Many-body Hamiltonians
Quantum Dynamics with scars
Realization of states with broken Zn symmetries n=2,3,4 with Rydberg atoms
The dipole model
Effective dipole Hamiltonian
The model has a straightforward representation in terms of Ising spins
Periodic drive and Magnus expansion
We study a simple square pulse protocol
Analytical calculation of HF: Magnus expansion
Derivation of Ow Floquet Hamiltonian
Dynamics of the Correlation function
High frequency regime: Lambda/Omega 1
Intermediate frequency regime Lambda/Omega 01
Phase diagram for the periodically driven Rydberg chain
Noisy dynamics
Square pulses with random drive period
The leading term of the commutator C = [U+, U_] may vanish at special drive frequencies
Analytical prediction of regions where random drive would lead to coherent oscillations
Dynamics around Gamma ~ Pi
Noise induced coherent dynamics around dT/T=1/4, 3/4.
Dynamics around Gamma ~ 2Pi
Conclusion
Q&A