IQIM Postdoctoral and Graduate Student Seminar

Abstract: Advances in the past decade have enabled the demonstration of solid-state qubit architectures with either high coherence or strong interactions. Well-isolated systems such as electronic and nuclear spin qubits in solids can have coherence times beyond one second but typically suffer from weak multi-qubit interactions. In contrast, superconducting quantum circuits enable strong multi-qubit interactions but have coherence times limited to hundreds of microseconds. A major challenge now is to develop architectures that can create strong interactions between qubits with long coherence times. 
In this talk, I will discuss two approaches that might address this challenge. I will first discuss our recent experiments in the Lukin Group at Harvard using the negatively charged silicon-vacancy color center in diamond. Following a brief introduction to the electronic and optical properties of this system, I will discuss experiments that demonstrate ten millisecond qubit coherence and GHz-bandwidth, high-cooperativity interactions with single optical photons. I will then present ongoing work in the Painter Group towards coupling nanomechanical resonators to superconducting qubits using piezoelectric materials. These mechanical modes are highly isolated quantum systems with a compact footprint, and can have lower dissipation rates compared with planar superconducting resonators and qubits.