The electron microscope as a quantum gate

TL;DR

This paper proposes using the topological charge of electrons in a transmission electron microscope as a quantum bit, enabling quantum logic operations with existing TEM technology.

Contribution

It introduces a novel approach to encode qubits in electron topological charge and demonstrates how TEM components can implement quantum gates.

Findings

Topological charge can serve as a qubit in TEM.

Magnetic quadrupoles and drift tubes can manipulate these qubits.

Potential for quantum computing experiments in existing TEMs.

Abstract

We propose to use the topological charge instead of the spin variable to span a two-dimensional Hilbert space for beam electrons in a transmission electron microscope (TEM). In this basis, an electron can be considered as a qbit freely floating in vacuum. We show how a combination of magnetic quadrupoles with a magnetic drift tube can serve as a universal device to manipulate such qbits at the experimenter's discretion. High-end TEMs with aberration correctors, high beam coherence and utmost stability are a promising platform for such experiments, allowing the construction of quantum logic gates for single beam electrons in a microscope.