Semiconductor quantum transistor opens door for photon-based computing

Roughly one million of these new transistors could fit inside a single grain of salt.

Researchers used a single photon, stored in a quantum memory, to toggle the state of other photons. (Image credit: E. Edwards/JQI)
Researchers used a single photon, stored in a quantum memory, to toggle the state of other photons. (Image credit: E. Edwards/JQI)

Researchers at the University of Maryland’s A. James Clark School of Engineering and Joint Quantum Institute (JQI) have cleared a hurdle in the development of such quantum-compatible hardware with their demonstration of the first single-photon transistor using a semiconductor chip.

Researchers can utilize numerous sorts of quantum particles as qubits, even the photons that make up light. Photons have included interest since they can quickly carry data over long distances, and they are good with fabricated chips. In any case, making a quantum transistor activated by light has been testing since it requires that the photons communicate with each other, something that doesn’t commonly happen.

The Maryland research group has utilized a quantum memory to influence photons to collaborate, making the main single-photon transistor produced using a semiconductor.

The gadget has various holes in it, influencing it to seem much like a honeycomb. Light entering the chip bounces around and gets caught by the opening example. A little precious stone sits inside the region where the light power is most grounded, and, closely resembling conventional computer memory, this crystal stores data about photons as they enter the device. It would then be able to successfully take advantage of that memory to intercede collaborations with different photons that later touch base at the chip.

The group observed that a single photon could, by connecting with the crystal, could control the transmission of a second light pulse through the device. The primary light pulse acts like a key, opening the entryway for the second photon to enter the chip. In the event that the primary pulse didn’t contain any photons, the crystal blocked resulting photons from overcoming.

This conduct is more like a traditional transistor where a little voltage controls the section of current through its terminals. Here, the scientists effectively supplanted the voltage with a single photon and showed that their quantum transistor could switch a light pulse containing around 30 photons before the devices’ memory ran out.

Institute for Research in Electronics and Applied Physics Affiliate Edo Waks said, “Using our transistor, we should be able to perform quantum gates between photons. Software running on a quantum computer would use a series of such operations to attain exponential speedup for certain computational problems.”

Lead author Shuo Sun, a postdoctoral research fellow at Stanford University said, “With realistic engineering improvements their approach could allow many quantum light transistors to be linked together. Such speedy, highly connected devices will eventually lead to compact quantum computers that process large numbers of photonic qubits.”

Their device, described in the July 6 issue of Science.