报告题目：Noise, Decoherence, and Parameter Shifts in Silicon-based Qubit Devices

报 告 人：Robert Joynt, University of Wisconsin-Madison

报告时间：2026年3月23日（星期一）下午16:00

报告地点：物理楼 W105

内容摘要：Electric field noise is a source of several harmful effects in quantum-dot quantum computers. I will start with a general introduction to this noise, whose sources are not well understood. I will describe some theoretical tools based on Bayesian inference that we have developed in order to deduce the physical nature of the sources from experimental data. The most important consequence of the noise is decoherence, but I will argue that it also causes the qubit frequencies to drift. This is also an issue for the smooth operation of a quantum computer.

报告人简介：Robert Joynt received his Ph.D. from the University of Maryland in 1982 and was a postdoctoral fellow at the Cavendish Laboratory of the University of Cambridge and the Institute for Theoretical Physics at ETH-Zurich. From 1986-2023 he was Professor of Physics at the University of Wisconsin-Madison, where he also served as Department Chair.  His research in condensed matter physics has ranged from the quantum Hall effect to high-Tc superconductivity to superfluidity in neutron stars. In quantum computing, active areas include semiconductor qubits, quantum correlations, and error correction schemes for neutral atom systems. At present he is researching ways to speed up the quantum optimization algorithms, decoherence from evanescent-wave Johnson noise, and new designs for qubit devices.