Open Quantum Systems
Any controllable quantum system must interact with the outside world, and with that interaction comes the unwanted effect of decoherence or dissipation. Deriving accurate models to describe decoherence, testing the validity of effective models, and understanding the impact of decoherence on quantum computing are research directions I am deeply passionate about.
My research has touched on all of these aspects: microscopic derivation of the dispersive regime cQED master equation [4]; demonstrating that quantum stochastic walks cannot be engineered without complete knowledge of the system Hamiltonian [3]; and understanding how even small amounts of frequency asymmetry in decay rates can drastically change the noise spectrum of the output of a travelling wave parametric amplifier [1].
While often considered harmful to quantum information processing, the goal of reservoir or dissipation engineering is to control and leverage decoherence to achieve a desired task. Often, the goal is to stabilize an entangled state, as my collaborators and I showed could be done in a Bose-Hubbard dimer setup of two bosonic modes [2].
Selected Papers
M. Houde, L. C. G. Govia, and A. A. Clerk, “Loss asymmetries in quantum travelling wave parametric amplifiers”, Phys. Rev. Applied 12 (3), 034054 (2019).
M. Mamaev, L. C. G. Govia, and A. A. Clerk, “Dissipative stabilization of entangled cat states using a driven Bose-Hubbard dimer”, Quantum 2, 58 (2018).
B. G. Taketani, L. C. G. Govia, and F. K. Wilhelm, “On the physical realizability of quantum stochastic walks”, Phys. Rev. A 97 (5), 052132 (2018).
L. C. G. Govia and F. K. Wilhelm, “Unitary-feedback-improved qubit initialization in the disper- sive regime”, Phys. Rev. Applied 4, 054001 (2015).