Recipes for spin-based quantum computing

Abstract

Technological growth in the electronics industry has historically been measured by the number of transistors that can be crammed onto a single microchip. Unfortunately, all good things must come to an end; spectacular growth in the number of transistors on a chip requires spectacular reduction of the transistor size. For electrons in semiconductors, the laws of quantum mechanics take over at the nanometre scale, and the conventional wisdom for progress (transistor cramming) must be abandoned. This realization has stimulated extensive research on ways to exploit the spin (in addition to the orbital) degree of freedom of the electron, giving birth to the field of spintronics. Perhaps the most ambitious goal of spintronics is to realize complete control over the quantum mechanical nature of the relevant spins. This prospect has motivated a race to design and build a spintronic device capable of complete control over its quantum mechanical state, and ultimately, performing computations: a quantum computer. In this tutorial we summarize past and very recent developments which point the way to spin-based quantum computing in the solid-state. After introducing a set of basic requirements for any quantum computer proposal, we offer a brief summary of some of the many theoretical proposals for solid-state quantum computers. We then focus on the Loss-DiVincenzo proposal for quantum computing with the spins of electrons confined to quantum dots. There are many obstacles to building such a quantum device. We address these, and survey recent theoretical, and then experimental progress in the field. To conclude the tutorial, we list some as-yet unrealized experiments, which would be crucial for the development of a quantum-dot quantum computer.

45 pages, 12 figures (low-res in preprint, high-res in journal) tutorial review for Nanotechnology; v2: references added and updated, final version to appear in journal

References in corpus (13)

• Hyperfine interaction in a quantum dot: Non-Markovian electron spin dynamics
• Zeeman energy and spin relaxation in a one-electron quantum dot
• Charge detection enables free-electron quantum computation
• Production and detection of entangled electron-hole pairs in a degenerate electron gas
• Optical Read-Out and Initialization of an Electron Spin in a Single Quantum Dot
• Electron spin phase relaxation of phosphorus donors in nuclear spin enriched silicon
• Measurement efficiency and n-shot read out of spin qubits
• Mesoscopic one-way channels for quantum state transfer via the Quantum Hall Effect
• Controlling Spin Qubits in Quantum Dots
• Lower bound for electron spin entanglement from beamsplitter current correlations
• Optical Detection of Single-Electron Spin Decoherence in a Quantum Dot
• Coulomb scattering in a 2D interacting electron gas and production of EPR pairs
• One-spin quantum logic gates from exchange interactions and a global magnetic field

Cited by in corpus (4)

• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Recent advances in exciton based quantum information processing in quantum dot nanostructures
• Intrinsic phonon decoherence and quantum gates in coupled lateral quantum dot charge qubits
• Cotunneling current through quantum dots with phonon-assisted spin-flip processes