We investigate a wide range of systems including superconducting quantum circuits, color centers, integrated photonics and phononics. Our projects present a balance of fundamental and applied research related to solid-state quantum devices. Current research directions include:

Quantum coherence and transduction in superconducting quantum circuits

Phonon- and defect- engineered superconducting qubits. Device credit: Mutasem Odeh, 2023

Superconducting quantum circuits are currently the leading solid-state quantum computing platform. Despite their remarkable progress, we are yet to fully understand and control dominant dissipation mechanisms that lead to high physical qubit error rates. We study and engineer how superconducting qubits interact with defects and phonons to enable higher-coherence qubits, quantum transducers, and quantum memories. Recent topics include:

  • Next-generation superconducting qubits via phononics [Ref. 1]

  • Quantum transduction between superconducting qubits, phonons, single spins, and optical photons [Ref. 2]

  • Microscopic origins of dielectric loss [Ref. 3] 

  • Coherence in electromechanical quantum systems [Ref. 4]

  • Materials origins of qubit-phonon interactions 

Quantum photonics with spin-photon interfaces in silicon 

Illustration of a silicon photonic crystal array containing quantum emitters. Device credit: Lukasz Komza, 2023

Silicon is the ideal material platform for building electronic and photonic circuits at scale. We are developing quantum nonlinear silicon photonics that will enable deterministic interactions between single photons and spin qubits for quantum communication and computation. To achieve this, we are developing spin-photon interfaces in integrated silicon photonics. The questions we study include: 

  • Color center qubits in silicon: How do we design an “ideal” atom-like, color center qubit in silicon? What are the desired defect symmetries, spin, electronic and optical properties? References: [1], [2]

  • Device integration: Integration of artificial atoms into silicon photonics to realize deterministic spin-photon, photon-photon, and long range spin-spin interactions at high bandwidths. References: [3]

  • Quantum repeater nodes: Developing a practical quantum repeater node based on silicon color centers for the UC Berkeley – LBL Quantum Network Testbed. 

Our long-term vision is to develop the missing ingredients that would enable practical quantum computers and communication nodes at silicon foundries. 

Please check out our publications and recent recorded talks (2023, 2021) to learn more about our work.