Generation of n-qubit W states using Spin Torque

TL;DR

This paper proposes a scheme to efficiently generate n-qubit W states using all-to-all exchange interactions, leveraging superposed excitations, within spin torque quantum architectures, achieving logarithmic stage complexity.

Contribution

It introduces a novel method for creating W states in spin torque systems with a logarithmic number of steps, formalizing bounds on excitation transfer.

Findings

Scheme achieves W state generation in O(log n) stages.

Formal bounds on maximal excitation jumps from q to n.

Demonstration within spin torque quantum computing architecture.

Abstract

We examine here a scheme to generate a W state of an n-qubit system with all-to-all pairwise exchange interaction between n qubits. This relies on sharing of superposed excitations of a smaller number of $q$ qubits among others. We present a bound on the maximal jumps from q to n and formalize a scheme to generate $W_n$ state in $\mathcal{O}(\log_4 n)$ stages. We demonstrate this scheme in the context of spin torque based quantum computing architecture that are characterized by repeated interactions between static and flying qubits.