In this thesis we present a spin based QuBit Architecture that implements single-QuBit gates in the QuBit itself and is predicted to have a long coherence time. This architecture has been physically realized in a Ferromagnetic Double Quantum Dot hosted in a Single Wall Carbon Nanotube, and studied through a coupled Microwave cavity. We present a Linear Response Theory model that ties the transmitted amplitude and phase of the microwave signal through the cavity to the microscopic charge susceptibility of the Double Quantum Dot. We fit those two channels of experimental data to a simple 4 level master equation model that allows us to extract the inter-dot tunneling rate, the charge-photons coupling rate and the charge dephasing rate. We also present a numerical algorithm that allows to evolve in time the quantum state of the device also considering the effect of charge noise. This algorithm is used to study the effect of fast Landau-Zener style pulses on the QuBit, giving the ideal shape of the control pulses.

Towards Single Spin Manipulation in a cQED Architecture

Vicentini, Filippo
2016/2017

Abstract

In this thesis we present a spin based QuBit Architecture that implements single-QuBit gates in the QuBit itself and is predicted to have a long coherence time. This architecture has been physically realized in a Ferromagnetic Double Quantum Dot hosted in a Single Wall Carbon Nanotube, and studied through a coupled Microwave cavity. We present a Linear Response Theory model that ties the transmitted amplitude and phase of the microwave signal through the cavity to the microscopic charge susceptibility of the Double Quantum Dot. We fit those two channels of experimental data to a simple 4 level master equation model that allows us to extract the inter-dot tunneling rate, the charge-photons coupling rate and the charge dephasing rate. We also present a numerical algorithm that allows to evolve in time the quantum state of the device also considering the effect of charge noise. This algorithm is used to study the effect of fast Landau-Zener style pulses on the QuBit, giving the ideal shape of the control pulses.
2016-09
87
cQED, DQD, QuBit, Quantum Information
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.12608/28458