  A notorious problem in high-resolution biological electron microscopy is
radiation damage to the specimen caused by probe electrons. Hence, acquisition
of data with minimal number of electrons is of critical importance. Quantum
approaches may represent the only way to improve the resolution in this
context, but all proposed schemes to date demand delicate control of the
electron beam in highly unconventional electron optics. Here we propose a
scheme that involves a flux qubit based on a radio-frequency superconducting
quantum interference device (rf-SQUID), inserted in essentially a conventional
transmission electron microscope. The scheme significantly improves the
prospect of realizing a quantum-enhanced electron microscope for
radiation-sensitive specimens.
