In the popular movie franchise Back to the Future, an eccentric scientist creates a time machine that runs on a flux capacitor. But, scientists at Australia (RMIT University, University of Queensland) and Switzerland (ETH Zurich) have make it a reality. They have developed a similar device that can break time-reversal symmetry.
The device, in other words, a new generation of electronic circulators – devices that control the direction in which microwave signals move. It is expected to help in future technologies such as a quantum computer. It could also lead to better electronics for mobile phones and wifi.
Scientists propose two diverse conceivable circuits, one of which looks like the iconic three-pointed-star design of the motion capacitor that they find in the Back to the Future movies.
It involves a combination of magnetic fields and electric charges leads to what the physicists call “broken time-reversal symmetry”.
RMIT’s Professor Jared Cole said, “The device proposed in the research was built from a superconductor, in which electricity can flow without electrical resistance. In this circuit, quantum ‘tubes’ of magnetic flux can move around a central capacitor by a process known as quantum tunneling, where they overcome classically insurmountable obstacles.”
Professor Tom Stace, from the University of Queensland, said, “This effect does not allow us to actually travel back in time. Instead, it means that signals circulate around the circuit in only one direction, much like cars on a roundabout.”
“Such a device can be used to isolate parts of an experimental apparatus from one other, which is critical when the individual parts are extremely sensitive quantum systems.”
Lead author Dr. Clemens Mueller, ETH Zurich, said the device was a crucial component for next-generation technologies, including the long-sought-after quantum computer.
“Our research makes an important step towards scaling up this technology, where researchers need to precisely direct control and measurement signals around a quantum computer.”
The paper is published in Physical Letters (DOI 10.1103/PhysRevLett.120.213602).
The research is part of a collaboration between two Australian Research Council Centres of Excellence: the ARC Centre for Future Low-Energy Electronics Technologies (FLEET) and the ARC Centre of Excellence for Engineered Quantum Systems (EQUS).