## Program

#### SESSION 12: Semiconductor qubits

Chair: (Kai-Mei Fu)
1:30pm - 2:15pmJason Petta, Princeton University (invited)
Towards microwave assisted spin-spin entanglement
Abstract. Electron spins are excellent candidates for solid state quantum computing due to their exceptionally long quantum coherence times, which is a result of weak coupling to environmental degrees of freedom. However, this isolation comes with a cost, as it is difficult to coherently couple two spins in the solid state, especially when they are separated by a large distance. Here we combine a large electric-dipole interaction with spin-orbit coupling to achieve spin-photon coupling. Vacuum Rabi splitting is observed in the cavity transmission as the Zeeman splitting of a single spin is tuned into resonance with the cavity photon. We achieve a spin-photon coupling rate as large as $$g _s/2 {\pi}$$ = 10 MHz, which exceeds both the cavity decay rate $${\kappa}/2{\pi}$$ = 1.8 MHz and spin dephasing rate $${\gamma}/2{\pi}$$ = 2.4 MHz, firmly anchoring our system in the strong-coupling regime. Moreover, the spin-photon coupling mechanism can be turned off by localizing the spin in one side of the double quantum dot. Recent progress towards microwave assisted spin-spin entanglement will be presented.
2:15pm - 2:45pmTyler Keating, HRL Laboratories
Spin-blockade spectroscopy of Si/SiGe quantum dots
Abstract. Many exchange-based platforms for spin qubits rely on spin-to-charge conversion for initialization and readout. The robustness of spin-to-charge conversion depends on the singlet-triplet energy splitting of two electrons occupying one dot, which is set by the energy of the dot's lowest-lying excited state. We demonstrate a model-independent technique to measure this energy, using repeated single-shot measurement across the spin-to-charge window. In our Si/SiGe triple dot device, we find that excitation energies vary smoothly with nearby gate bias, suggesting that the lowest-lying states are orbital in character. We also consider other, model-specific parameters that could be extracted from this type of measurement.

SQuInT Chief Organizer
Akimasa Miyake, Associate Professor
amiyake@unm.edu

SQuInT Local Organizers
Rafael Alexander, Postdoctoral Fellow
Chris Jackson, Postdoctoral Fellow