Possible use of a Cooper-pair box for low-dose electron microscopy

TL;DR

This paper proposes a quantum-enhanced electron microscope using a Cooper pair box to improve phase measurement precision for radiation-sensitive biological specimens, aiming to approach the Heisenberg limit.

Contribution

Introduction of a superconducting quantum circuitry design with a Cooper pair box to enhance phase measurement in low-dose electron microscopy.

Findings

Potential to significantly improve phase measurement precision.

Design could approach the Heisenberg limit with delocalized inelastic scattering.

Applicable to imaging radiation-sensitive biological samples.

Abstract

A transmission electron microscope that takes advantage of superconducting quantum circuitry is proposed. The microscope is designed to improve image contrast of radiation-sensitive weak phase objects, in particular biological specimens. The objective in this setting is to measure the phase shift of the probe electron wave to a precision $\Delta\theta$ within the number of electrons $N$ that does not destroy the specimen. In conventional electron microscopy $\Delta\theta$ scales as $\sim 1/N^{1/2}$, which falls short of the Heisenberg limit $\sim 1/N$. To approach the latter by using quantum entanglement, we propose a design that involves a Cooper pair box placed on the surface of an electrostatic electron mirror in the microscope. Significant improvement could be attained if inelastic scattering processes are sufficiently delocalized.