How to Detect a Stream of Microwave Photons

How to Detect a Stream of Microwave PhotonsA new device converts a stream of microwave photons into an electric current with high efficiency, which will benefit quantum information technologies.By Mark Buchanan T echnologies for quantum computing, sensing, and communication process information stored in quantum bits (qubits) by using microwave photons.But detecting such photons accurately and at high rates-to read out the changing states of a quantum computer, for example-is a challenge, since they have much less energy than visible or infrared photons.Now researchers have demonstrated a Help arrives.This schematic image shows a microwave photon (red) being transmitted through an antenna-like wire made of granular aluminum called a resonator to a tunnel junction (intersection of the gray bars).The absorption of this photon by an electron (sphere) allows the electron to cross the junction, where it signals the presence of the photon.Detecting microwave photons rapidly and efficiently will be essential for future quantum information technologies