Events at Physics |
Events on Monday, August 23rd, 2021
- Academic Calendar
- Graduate School Fall 2021: Fall degree window period begins
- Abstract: *Important Note: The “Window Period” is the time between the end of one degree period and the beginning of the next. You must have been registered for the previous semester (Fall, Spring, or Summer). If all degree requirements are met by the end of the window period, your degree will be granted for the following semester. However, you will not have to register or pay fees for the next semester. CONTACT: 262-2433, gsacserv@grad.wisc.edu
- Thesis Defense
- Coherent and cavity-based measurement of two-particle states
- Time: 4:00 pm
- Place: Zoom link below
- Speaker: Joelle Corrigan, Physics PhD Graduate Student
- Abstract: With their small footprint and compatibility with industry fabrication techniques, semiconducting quantum dots have shown great potential as a platform for quantum computing.Though one of the most basic qubit implementations requires only a single electron within one quantum dot, many other platforms or readout schemes involve coupling between multiple quantum dots and differentiating between two-particle, singlet-triplet states. In silicon or Si/SiGe systems, the most basic singlet-triplet splitting depends on the valley state, which is much lower than the quantum dot’s potential-defined orbital state and can vary widely based on dot confinement and position (typically 5-40GHz). In this talk I first introduce a tunable latched readout scheme and demonstrate its use in charge-mapped readout of the quantum dot hybrid qubit. This scheme is then used to characterize a series of two-particle states using both Rabi and Ramsey pulsing, revealing 8 different transitions below 10GHz. The presence of these low energy levels is explained by considering electron-electron interactions within the system, and the data are fit using a six-level Hamiltonian. The last part of the talk will focus on a 3D integrated resonator-dot system. Driving the double-quantum-dot detuning at the cavity frequency reveals an enhanced coupling response of the cavity to the double-quantum-dot tunneling transition. This response is fit to using theory for a modulated longitudinal coupling between the dots and the cavity to good agreement. Finally, fast dc pulses are used to probe the singlet-triplet splitting in the system by populating excited states in the quantum dot. Join Zoom Meeting Meeting ID: 408 330 5280 Passcode: qubit
- Host: Mark Eriksson, Faculty Advisor