Our current research interests are in the area of quantum information science and technology, specifically in the context of superconducting qubits:
- development of novel superconducting circuits with enhanced protection from decoherence due to external noise sources,
- quantum optimal control of ordinary and protected qubits in the 2d and 3d cQED architecture, and
- autonomous quantum error correction.
Heavy fluxonium coupled to an LC oscillator, as realized in David Schuster’s lab (see article here).
Engineered quantum systems provide an exciting platform for exploring quantum physics in an active way. Rather than observing and interpreting quantum effects exhibited by nature, the objective is to design quantum devices for specific purposes. The most prominent example is the goal of realizing a quantum computer. Superconducting qubits and circuit QED provide us with a promising hardware architecture to reach this goal.
Our research follows two main thrusts: the theoretical study of nonequilibrium physics and dissipative phase transitions of interacting photons in circuit QED arrays, and the improvement of coherence and control of the next generation of superconducting qubits. Most of our work is carried out in close collaboration with the labs of David Schuster (University of Chicago) and Andrew Houck (Princeton University).
This animation shows the time evolution of the Wigner function for the state of an undriven anharmonic oscillator. The initial state is a coherent state, which can be thought of as a coherent superposition of Fock states. The presence of the Kerr nonlinearity causes the Fock states to acquire relative phases as time progresses, leading to interesting geometric patterns. Often, these take the form of discrete superpositions of multiple coherent states, such as cat states. Over a time period determined by the nonlinearity, the phases align such that state refocuses back into a regular coherent state.
Animation by Aditya Gandotra