Synthetic Lattice for a Single Photon ⚡ экспресс
By creating a synthetic frequency lattice (an artificial set of equally spaced frequencies through which photons can move), scientists have realized for the first time the quantum evolution of single photons in such a structure. To do this, a superconducting qubit was connected to a 16-meter aluminum coaxial cable, and a tunable modulator based on a SQUID (superconducting quantum interference device) mimicked couplings and magnetic fields. Quantum random walks and Bloch oscillations of photons were observed, along with directional frequency conversion under fast modulation. Importantly, the lattice can be dynamically reconfigured into a multidimensional one—like changing a maze for light "balls" on the fly. This paves the way to programmable quantum simulators.
A photon is like a car in a multi-story parking lot, where each floor is its frequency (color). Usually it gets stuck on one level, but scientists added an elevator — a programmable modulator that moves the photon between floors on command. This elevator creates links between frequencies, turning them into an artificial lattice, reminiscent of the method of studying light by its frequencies — spectroscopy.
By changing the elevator’s mode, you can get the photon to wander randomly across floors, rhythmically swing up and down, or strictly move only upward with no return. In the experiment, a single photon was born in a superconducting qubit — an artificial atom developed thanks to the discoveries of Bardeen — and raced along a 16-meter cable at nearly the speed of light. The statistics of its jumps obeyed laws studied by Roy Glauber.
🎯 The 16-meter cable length isn’t random: it set the spacing between frequency floors at about 10 MHz so they could be resolved and controlled individually.