Quantum information processing in semiconductor nanostructures

TL;DR

This paper explores two semiconductor nanostructure schemes for quantum information processing, including optical entanglement and NMR-based quantum gates, addressing decoherence and implementation challenges.

Contribution

It presents novel methods for entanglement generation and quantum gate implementation in semiconductor quantum dots, advancing solid-state quantum computing.

Findings

Optical pulses can generate Bell and GHZ states in quantum dots.

Proposed NMR-based quantum gates with long coherence times.

Discussion of decoherence effects in quantum dot systems.

Abstract

A major question for condensed matter physics is whether a solid-state quantum computer can ever be built. Here we discuss two different schemes for quantum information processing using semiconductor nanostructures. First, we show how optically driven coupled quantum dots can be used to prepare maximally entangled Bell and Greenberger-Horne-Zeilinger states by varying the strength and duration of selective light pulses. The setup allows us to perform an all-optical generation of the quantum teleportation of an excitonic state in an array of coupled quantum dots. Second, we give a proposal for reliable implementation of quantum logic gates and long decoherence times in a quantum dots system based on nuclear magnetic resonance (NMR), where the nuclear resonance is controlled by the ground state transitions of few-electron QDs in an external magnetic field. The dynamical evolution of these systems in the presence of environmentally-induced decoherence effects is also discussed.