Optical manipulation of quantum dot spin qubits with exciton-polariton resonance
- Experiments to manipulate a handful of quantum bits, based on a variety of underlying physical mechanisms, have been demonstrated. The ultimate goal is to build large systems consisting of billions of qubits and implement fast qubit operations with adequate accuracy, for solving problems that are intractable on classical computers (like factoring large numbers and quantum simulations). We develop and analyze a hardware platform for a scalable quantum computer based on semiconductor quantum dot (QD) electron spin qubits and their interaction with microcavity quantum well (QW) exciton-polaritons. This approach is based on the framework of previously proposed QuDOS architecture for surface code quantum computation. Despite the developments in techniques for implementing quantum non-demolition (QND) measurement and nearest-neighbor gates in QD spin systems, achieving the resource requirements for fault-tolerance still remains a challenge. In order to overcome this, our scheme relies on the indirect optical control of QD spins, resulting from the long-ranged Coulomb exchange interaction between the spin qubits and optically excited, spin-polarized, QW exciton-polaritons. The strength of this scheme is twofold. Firstly, by a careful design of the QW and QD it is possible to separate the optical eld from the QD manifold, thus preventing any unwanted backaction during a measurement event. Secondly, the bosonic nature of polaritons and their weak interaction with the solid-state environment allows the injection of numerous polaritons coherently in a single mode, increasing the nonlinearity in the qubit-polariton coupling, crucial for two-qubit operation. We develop schemes for implementing fast, high- delity, single qubit gate, two-qubit geometric phase gate and single-shot QND measurement. Furthermore, we investigate several issues critical for the robustness of the gate operations such as decoherence mechanisms, polariton-polariton interaction, phonon scattering etc.
|Type of resource
|electronic; electronic resource; remote
|1 online resource.
|Stanford University, Department of Applied Physics.
|Statement of responsibility
|Submitted to the Department of Applied Physics.
|Thesis (Ph.D.)--Stanford University, 2014.
- © 2014 by Shruti Puri
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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