In our group, we study the interaction between microwave fields and nonlinear microwave oscillators. These nonlinear oscillators are formed form the Josephson junctions, the building blocks of superconducting circuits. By operating at ultralow temperatures, we can study this interaction in the regime where quantum mechanics is dominant. In addition to providing a model system for understanding the interplay between nonlinearity and quantum mechanics, these oscillators also perform useful analog signal processing in the quantum regime. For example, with these oscillators we build microwave amplifiers that operate at the quantum limit and microwave amplifiers which can circumvent that limit. Current work focuses on using these nonlinear oscillators to create entanglement of microwave photons, and to use that entanglement to teleport quantum states.

In related work, we study the interaction of nanomechanical resonators with microwave fields. We demonstrate that by coupling to microwaves it is possible to detect the resonator's motion sensitively enough to observe its zero-point motion. Furthermore, the microwave field can be used to cool the resonantor to its motional ground state, allowing these classical resonators to inheret the quantum properties of the microwave field. Current work focuses on using the strong interactions between microwaves and mechanical motion to create ultrasensitive force detectors, and to provide a memory element that can transfer and retrieve a microwave signal from mechanical motion.

key words

Nanomechanics; Quantum limited amplification; Quantum information; Squeezing; Entanglement; Parametric amplifier; Josephson junction; Metamaterial;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants