Quantum Gates by Coupled Quantum Dots and Measurement Procedure in Field-effect-transistor Structure

Abstract

Coupled quantum‐dot system in semiconductor is considered to be one of the promising candidates of quantum computer. It will be most desirable that the quantum computing devices are implemented into the same substrate as the widely used LSI circuits. From this viewpoint, the quantum computer of coupled quantum dots of semiconductors is presented concentrating on the controlled‐NOT‐gate operation. The decoherence time of the quantum computation and the measurement procedure by field‐effect‐transistor structure are discussed.

Quantum Information Transfer from a Double Quantum Dot System to a Cavity Field

“…One approach to build a solid-state quantum computer is by exploiting quantum states of artificial atoms (quantum dots) [6−7] and molecules (coupled quantum dots). [8] Present-day nanofabrication technology allows us to design quantum-dot atoms and quantum-dot molecules, in which atomic (molecular)-like electronic states can be controlled with external fields. Semiconductor quantumdot charge-based qubits were first considered in 1995 by Barenco and coworkers [9] where quantum information was encoded in excitation levels and later by Fedichkin et al for position-based charge qubits in GaAs.…”