BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:5 UID:UW-Physics-Event-8402 DTSTART:20231214T213000Z DTEND:20231214T230000Z DTSTAMP:20260413T225818Z LAST-MODIFIED:20231127T154345Z LOCATION:Discovery Building\, DeLuca Forum SUMMARY:Under the hood: microscopic noise characterization in semicond uctor quantum dots\, Wisconsin Quantum Institute Colloquium\, John Nic hol\, University of Rochester DESCRIPTION:

Electron spins in silicon quantum dots are excellent qu bits due to their long coherence times\, scalability\, and compatibili ty with advanced semiconductor technology. Even though single- and two -qubit gates with fidelities above 99% have been achieved in Si spin q ubits\, charge noise in the semiconductor environment still hinders ga te fidelities. Despite the importance of charge noise\, key questions like what specific defects cause the noise\, where they are in the dev ice\, and how they are thermalized\, remain unanswered. I will discuss recent work probing individual two-level fluctuators (TLFs) in Si/SiG e quantum dots via simple transport measurements. We find that the TLF s depend sensitively on gate voltage and temperature. We also find tha t the TLFs are likely not described by a model involving isolated dipo le fluctuators coupled to a phonon bath\, and that current through the quantum dot appears to heat the TLFs. These measurements open up new pathways for detailed characterization of noise sources in spin qubits .

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This event starts at 3:30pm with refreshments\, followe d at 3:45pm by a short presentation by Ben Harpt (PhD student Mark Eri ksson group) titled "Longitudinal electron-photon coupling in a quantu m-dot qubit: expanding the toolbox for quantum engineers". The invited presentation starts at 4pm.

URL:https://www.physics.wisc.edu/events/?id=8402 END:VEVENT END:VCALENDAR