Qudit Quantum Computing

While most quantum processors encode binary information in a collection of two-level systems (qubits), the transmon circuit intrinsically features higher-level states that can be accessed. Using these levels, we are developing quantum processors that use N-level systems (qudits) as their elementary building block.

A qudit processor poses a resource-efficient way to increase the available Hilbert space and strongly reduce the number of required entangling gates (that are typically the most difficult to perform) for a given algorithm. To capitalize on the full potential of the higher-energy states in the transmon circuit, we are (1) designing circuits optimized for qudit coupling and readout, (2) employing quantum control techniques, inspired NMR and quantum optics, to perform high-fidelity single-and mulitple-qudit gates, and (3) exploring quantum computing, simulation -, and sensing protocols where qudits have advantage of qubits.