PhD Proposal: John Caporaletti
Location
Physics : 401
Date & Time
December 3, 2024, 12:00 pm – 1:30 pm
Description
ADVISOR: Dr. Jason Kestner
TITLE: Use of Excited States in Silicon Quantum Dots for Novel Qubits and Sensors
ABSTRACT: A charge qubit couples to environmental electric field fluctuations through its dipole moment, resulting in fast decoherence. We propose the p-orbital (pO) qubit, formed by the single-electron, p-like valence states of a five-electron Si quantum dot, which couples to charge noise through the quadrupole moment. Preliminary work demonstrates universal control of two pO qubits as well as distinct strengths in quality factor, gate speed/control, readout and size. In particular, an order of magnitude improvement in qubit quality factor is expected relative to state-of-the-art semiconductor spin qubits, assuming a phenomenological dipole two-level fluctuator noise model. Work in the first half of my PhD will primarily address scaling up to a large array of pO qubits. In the latter half, a shift in focus will be made to study an in-situ, charge noise sensor which utilizes an uncoupled, auxiliary qubit degree of freedom (DOF) to measure local charge noise without inadvertently disrupting the information bearing DOF. Valley/orbital probe-induced decoherence, modular probe architectures, and scalable feedback will be focused on.
TITLE: Use of Excited States in Silicon Quantum Dots for Novel Qubits and Sensors
ABSTRACT: A charge qubit couples to environmental electric field fluctuations through its dipole moment, resulting in fast decoherence. We propose the p-orbital (pO) qubit, formed by the single-electron, p-like valence states of a five-electron Si quantum dot, which couples to charge noise through the quadrupole moment. Preliminary work demonstrates universal control of two pO qubits as well as distinct strengths in quality factor, gate speed/control, readout and size. In particular, an order of magnitude improvement in qubit quality factor is expected relative to state-of-the-art semiconductor spin qubits, assuming a phenomenological dipole two-level fluctuator noise model. Work in the first half of my PhD will primarily address scaling up to a large array of pO qubits. In the latter half, a shift in focus will be made to study an in-situ, charge noise sensor which utilizes an uncoupled, auxiliary qubit degree of freedom (DOF) to measure local charge noise without inadvertently disrupting the information bearing DOF. Valley/orbital probe-induced decoherence, modular probe architectures, and scalable feedback will be focused on.
