Researchers Entangle Qubits with Magnets

Technique allows for more spacious quantum computers

Scientists at the University of Chicago, the Argonne National Laboratory, University of Iowa, and Japan’s Tohoku University have discovered a new technique for using magnets to entangle qubits. This method could one day lead to more efficient entanglement – and therefore more efficient and reliable quantum computers. Principal investigator David Awschalom, of the University of Chicago’s Pritzker School of Molecular Engineering, states, “This is a proof of concept, at room temperature, of a scalable, robust quantum technology that uses conventional materials...The beauty of this experiment is in its simplicity and its use of well-established technology to engineer and ultimately entangle quantum devices.”

A common technique for achieving entanglement is to use Nitrogen Vacancy (NV) centers – point defects in a diamond. The problem is that these NV centers normally have to be very close together.

According to the press release, “Two years ago, University of Iowa professor Michael Flatté and his collaborators published a theoretical paper that proposed using a magnetic material to make a quantum connection between NV centers so that they could be entangled while further apart. The normal interaction between two NV centers involves microwaves—in this proposed device, the magnet receives the microwave from the NV center and transmits it via “magnon” to the NV on the other side.

In a magnet, the spins of all the electrons inside it point in the same direction, like stalks of grain all pointing upward. A magnon is a slight wave disturbance through those spins, like a wave the wind would make across the field of grain. Magnons can go much further than nanometers—even a thousand times farther, in fact, to many micrometers.”

See the announcement at the University of Chicago website for additional information.