Encoded Universality of Quantum Computations on the Multi-Atomic Ensembles in the QED Cavity

TL;DR

This paper introduces a set of elementary quantum gates for multi-atomic systems in QED cavities, enabling universal quantum computation with error immunity and simplified implementation.

Contribution

It presents a new encoding and gate set that simplifies physical realization and enhances error resistance for solid-state quantum computers.

Findings

Universal quantum gates are achievable with three elementary gates.

Encoded controlled-NOT can be performed in a single step.

The approach improves implementation of common controlled gates.

Abstract

We propose an effective set of elementary quantum gates which provide an encoded universality and demonstrate the physical feasibility of these gates for the solid-state quantum computer based on the multi-atomic systems in the QED cavity. We use the two-qubit encoding and swapping-based operations to simplify a physical realization of universal quantum computing and add the immunity to a number of errors. This approach allows to implement any encoded single-qubit operation by three elementary gates and the encoded controlled- NOT operation can be performed in a single step. The considerable advantages are also shown for implementing some commonly used controlled gates.