Princeton University, Department of Physics
"Coherent Coupling of Spin and Light"
Tremendous progress has been achieved in the coherent control of single quantum states (single charges, phonons, photons, and spins). At the frontier of quantum information science are efforts to hybridize different quantum degrees of freedom. For example, by coupling a single photon to a single electron fundamental light-matter interactions may be examined at the single particle level to reveal exotic quantum effects, such as single atom lasing. Coherent coupling of spin and light, which has been the subject of many theoretical proposals over the past 20 years, could enable a quantum internet where highly coherent electron spins are used for quantum computing and single photons enable long-range spin-spin interactions. In this colloquium I will describe experiments where we couple a single spin in silicon to a single microwave frequency photon. The coupling mechanism is based on spin-charge hybridization in the presence of a large magnetic field gradient. Spin-photon coupling rates gs/2p > 10 MHz are achieved and vacuum Rabi splitting is observed in the cavity transmission, indicating single spin-photon strong coupling. These results open a direct path toward entangling single spins at a distance using microwave frequency photons.
About the speaker
Jason Petta's research group focuses on quantum control of nanometer scale systems. Semiconductor quantum dots are used to isolate single electron spins, which exhibit long quantum coherence times. These systems allow quantum mechanics to be harnessed in a solid state environment for the implementation of quantum gates. They use nanofabrication to create artificially structured systems with experimentally tunable Hamiltonians that can be controlled on sub-nanosecond timescales. Recent research examines strong light-matter interactions in the circuit quantum electrodynamics architecture, with a goal of generating long-range many body entanglement. Silicon and diamond are ideal host materials for spin coherence, leading to spin coherence times that now approach 10 seconds. A major effort in the group consists of developing a scalable quantum computing architecture in isotopically purified silicon. Research advances are enabled by a tight feedback loop that links nanoscale materials synthesis and advanced transport measurements.