Preliminary Exam |
Events on Monday, November 3rd, 2025
- Direct measurement of the energy spectrum of a quantum dot artificial molecule
- Time: 12:30 pm - 2:00 pm
- Place: Chamberlin Hall Room 5310
- Speaker: Jack Reily
- Abstract: Quantum dot artificial atoms in semiconducting SiGe/Si/SiGe heterostructures, formed by strong electronic confinement, are promising scalable qubit systems. The single- and few-electron spectra consist of multiple valley-orbital levels, which, in general, modify tunnel couplings and qubit dynamics, which is relevant for qubit encoding and readout. Here, we provide a new method of directly measuring the energy spectrum of an artificial molecule for fixed electron number. By tuning square wave pulses along the delta axis of the artificial molecule, we show how the curvature governed by excited-to-excited, ground-to-excited, and ground-to-ground couplings can all be extracted simultaneously. This new measurement provides the ability to extract many relevant Hamiltonian parameters, which are necessary for the precise operation and control of spin qubits.
- Host: Albrecht Karle