It consists of a 35-nanometer-wide film made out of an organic semiconductor sandwiched between two mirrors that create a microcavity, which keeps light trapped inside. When a bright “pump” laser is shone onto the device, photons from its beam couple with the material to create a conglomeration of quasiparticles known as a Bose-Einstein condensate, a collection of particles that behaves like a single atom.

A second weaker laser can be used to switch the condensate between two levels with different numbers of quasiparticles. The level with more particles represents the “on” state of a transistor, while the one with fewer represents the “off” state.

What’s most promising about the new device, described in a paper in Nature, is that it can be switched between its two states a trillion times a second, which is somewhere between 100 and 1,000 times faster than today’s leading commercial transistors. It can also be switched by just a single photon, which means it requires far less energy to drive than a transistor.