Southwest Quantum Information and Technology

Finite efficiency measurements and quantum back-action control of chaos

Presenting Author: Maya Khesin, Carleton College
Contributing Author(s): Yusuf Ismail (Carleton College), Sacha Greenfield (USC), and Arjendu K. Pattanayak (Carleton College)

Quantum backaction from weak measurement affects the dynamics of nonlinear quantum systems in intriguing and useful ways. Previous simulations showed that for an optical cavity based implementation of the driven Duffing oscillator, the phase setting ϕ for a laser used for measurement changes quantum dissipation. This can considerably alter the energy absorbed, enabling significant control including changing the quantum trajectory dynamics from regular to chaotic and vice-versa. We present new results on the effect of measurement information being discarded, in particular by tracing over trajectories with different stochastic realizations to recover a density matrix. Disparities between dynamics at different ϕ vanish when sufficiently large numbers of trajectories are sampled. We also report on how results interpolate between these for finite efficiency measurements, which requires a different formalism.

(Session 5 : Thursday from 5:00 pm - 7:00 pm)