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

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

SQuInT Administrator
Gloria Cordova
505 277-1850

SQuInT Assistant
Wendy Jay

SQuInT Founder
Ivan Deutsch, Regents' Professor, CQuIC Director

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