Transmission based tomography for spin qubits

TL;DR

This paper proposes a transmission-based tomography method for spin qubits using unpolarized flying qubits and scattering analysis to reconstruct the quantum states of static spin qubits in a one-dimensional channel.

Contribution

It introduces a novel scheme employing scattering of unpolarized qubits to perform state tomography on static spin qubits, enabling separate readout of one and two-qubit states.

Findings

Successfully reconstructs static qubit states from transmission data

Demonstrates the method's ability to distinguish between different qubit configurations

Provides a framework for non-invasive qubit state measurement

Abstract

We consider a system of static spin qubits embedded in a one-dimensional spin coherent channel and develop a scheme to readout the state of one and two qubits separately. We use unpolarized flying qubits for this purpose that scatter off from the static qubits due to the Heisenberg exchange interaction. Analysing the transmission coefficient as a function of density matrix elements along with additional unitary gates we reconstruct the state of static qubits.