Scientists Are Building a Microscope Powered by a Quantum Computer

Researchers in Austria — at TU Wien, the University of Vienna, Johannes Kepler University Linz and the University of Innsbruck — are building an electron microscope connected to a quantum computer, an approach they say could extract far more information from each electron than conventional microscopes do. A prototype is now being constructed at TU Wien.

Standard electron microscopes count electrons to build an image, even though each electron also carries quantum information that normally goes unused. "Today, we can image tiny details on the atomic scale," said Philipp Haslinger of TU Wien's Institute of Atomic and Subatomic Physics. "However, this requires a large number of electrons. And not every sample can be exposed to so many electrons without being damaged." That is a particular problem for delicate biological samples such as individual proteins.

The team's idea is to let electrons passing through the microscope interact with ions held in a trap along the beam's path, creating quantum entanglement between each electron and the quantum computer. Repeating this with electron after electron lets the system combine information from many electrons at once. "If we perform very specific quantum-computing operations each time, we can optimally combine the information from several electrons so that we obtain a signal of maximum strength even though we use only a relatively small number of electrons," said Dennis Rätzel, also of TU Wien.

What would previously have been indistinguishable from random noise can become a clear signal, said Iva Březinová of TU Wien's Institute for Theoretical Physics. "Quantum physics allows us to overcome the statistical limits that constrain conventional electron microscopes," added first author Elias Pescoller. So far the team has shown mathematically that the method should work; the next step is to demonstrate it experimentally, using an ion-based quantum computer built by a team at the University of Innsbruck.