Dissertation > Excellent graduate degree dissertation topics show

Coupled quantum measurement of the electronic spin states in a double quantum dot devices

Author: ZhangJianPing
Tutor: YouJianQiang
School: Fudan University
Course: Theoretical Physics
Keywords: coupled double quantum dots quantum point contact single electron spin readout rate equation spin quantum bits
CLC: O471.1
Type: Master's thesis
Year: 2008
Downloads: 113
Quote: 0
Read: Download Dissertation

Abstract


Quantum measurement of single electron spin states is an important topic in both fundamental aspects and potential applications of quantum information processing. In this thesis, we study the readout of single electron spin states in a double quantum dots (DQD) using a quantum point contact (QPC).In Chapter 1, we briefly review the quantum dot system and its physical properties such as quantum size effect, Coulomb blockade, Pauli spin blockade and quantum tunneling. Some of the concepts in this Chapter serves as the framework of the subsequent chapters.In Chapter 2, we introduce the basic knowledge regarding the readout the of single electron spin states. It includes the physical principle of single electron spin resonance and its experimental implementation, the Fermi contact hyperfine interaction between an electron spin in a quantum dot and many nuclear spins in the host material, and the application of the rate equations approach in electron transport through quantum dot.In Chapter 3, we present our main results. First, we briefly introduce experimental results obtained by others for the single electron spin readout in single quantum dot. Then, we study the dynamics of a single electron spin in a DQD and its readout via QPC. We model the system microscopically and derive rate equations for the reduced electron density matrix of the DQD. Two cases with one and two electrons in the DQD are studied. In the one-electron case (studied in Chapter 3), the electron spin states are distinctly characterized by a constant and an oscillatory current through the QPC. Moreover, to ensure that an electron is properly injected into the qubit dot, we propose to determine the success of the electron injection from the variations of the QPC current after applying an oscillating magnetic field to the qubit dot.In Chapter 4, we study the two-electron case, where the readout of the spin state of the electron in one of the dots called the qubit dot is essentially similar after considering hyperfine interactions between the electrons and the nuclear spins of the host materials and a uniform magnetic field applied to the DQD. Same as in the one-electron case, we determine the success of the electron injection again from the variations of the QPC current after applying an oscillating magnetic field to the qubit dot. Finally, we give a brief summary in Chapter 5.

Related Dissertations

  1. Intracavity frequency doubling Raman lasers and coherent anti-Stokes collinear phase matching theory,TN248
  2. The Study on the Kinetic Scaling Behavors of Aggregate Systems with Variety Catalysis-driven Aggregations,O643.3
  3. The Mechanism of the Degradation of DNS and Its Kinetics,O643.12
  4. Quantum point contact measurement of quantum dot system decoherence effects,O471.1
  5. LD-pumped Yb ion heat capacity laser feasibility study,TN248
  6. Research on Noise Models and Their Applications in Nano-Scale Semiconductor Devices,TN303
  7. Theoretical Study of Transport Properties of Coupled Quantum Dots Systems,O471.1
  8. Theoretical Research on Thulium-doped Fiber Lasers,TN248
  9. Research of Tunable Erbium Doped Ring Fiber Laser,TN248
  10. Experimental Research on Tm3+-doped Fiber Laser,TN248
  11. Frequency Upconversion Characteristics of Er3+Doped YVO4 Crystal,O73
  12. Research on LD Pumped Doul-Loss Q-Switched Mode-locked Lasers and Dynamic Thermal Modeling,TN248
  13. Study on Characteristics of All-Solid-State Q-switched Lasers with V3+:YAG Saturable Absorber at 1.3μm,TN248
  14. Nd: YAG ceramic laser theoretical and experimental studies, and TiO_2 light diffusion in random media research,TN248
  15. Synthesis and Nonlinear Optical Properties of Phthalocyanine Complex,O437
  16. Thermalchemical Resorption Refrigeration Driven by Low Grade Thermal Energy,TB61
  17. Electrochemically Enhanced Adsorption of Selected Organic Pollutants from Aqueous-solution on Activated Carbon Fibers,X703
  18. Efficient Luminescence and Characterization of Er3+-Yb3+-doped Mesoporous Sieves,TN722
  19. Researches on Thermal Effect and Photoelectricity Characteristic of VCSEL,TN248
  20. New ring cavity erbium-doped fiber laser,TN248

CLC: > Mathematical sciences and chemical > Physics > Semiconductor physics > Semiconductive Theory > Semiconductor quantum theory
© 2012 www.DissertationTopic.Net  Mobile