Electrical readout of a spin qubit without double occupancy

TL;DR

This paper introduces a new all-electrical method for reading out a single solid-state electron spin without double occupancy, enhancing quantum measurement fidelity and applicability.

Contribution

It presents a novel spin-to-charge conversion technique using three donors and two spins, avoiding double occupancy and potential electron loss.

Findings

Successful identification of a spin readout mechanism without double occupancy.

Potential for application in both electron and nuclear spin quantum computers.

Elimination of unwanted electron loss during readout.

Abstract

We identify a novel mechanism to read out a single solid-state electron spin using an all-electrical spin-to-charge conversion in a closed system. Our scheme uses three donors and two electron spins, one spin is the qubit, the other is a reference. The population in the third, originally ionized, donor is monitored with an electrometer. Energy-dependent tunnelling of the reference spin to the ionized donor is used to determine the state of the qubit. In contrast to previous methods [e.g., B.E. Kane, Nature (London), \textbf{393}, 133 (1998)] we avoid double electron occupancy of any site within the system, thereby eliminating the possibility of unwanted electron loss from the system. The single spin readout scheme described here is applicable to both electron and nuclear spin based quantum computer architectures.