Quantum computing and condensed matter physics with microwave photons

Research Projects

Circuit Quantum Electrodynamics

Microwave photons in a superconducting transmission line cavity are strongly coupled to a qubit, or "artificial atom," in direct analogy with optical cavity QED.  This a key component of everything we do, including superconducting quantum computing, hybrid quantum inofrmation, and quantum simulation.

Hybrid Quantum Computing

We are interested in coupling superconducting resonators to other (non-superconducting) quantum systems.  We are particularly focused on coupling to electron spin qubits in collaboration with other members of the Princeton Center for Complex Materials.

Condensed matter physics with photons

Photons do not in general interact.  However, in a cavity QED system, a qubit can mediate an effective interaction between photons.  In coupled arrays of such cQED elements, photons can hop between neighboring cavities and experience on-site interactions in any one cavity.  Such arrays are expected to support many-body states of photons and interesting matter-like behavior.  Because photon number is not a conserved quantity, such behavior is far from equilibrium and an area of particular interest.

Superconducting Quantum Computation

We explore superconducting qubits for purposes of quantum computation, focusing on improved elements of a quantum computer rather than implementation of small algorithms.  In particular, we are focused on new types of qubits, including a transmon-like qubit with tunable coupling, and improved measurement.