Defects in semiconductor enable qubits that emit photons in IR

An international research team has discovered a way to create qubits that emit photons at wavelengths close to those used by telecom providers. Scientists at the University of Groningen, together with colleagues from Linköping University and Norstel AB, constructed a qubit that transmits information on its status at a wavelength of 1100 nm. The team said that it is likely that the approach they used could be tuned to wavelengths of 1300 to 1500 nm.

The qubits were based on silicon carbide crystals in which molybdenum impurities created color centers that could respond to light of specific wavelengths. When the researchers shined light at a certain wavelength onto the color centers, they found that electrons in the outer shell of the molybdenum atoms in the silicon carbide were kicked to a higher energy level. When the atoms returned to their ground state, they emitted their excess energy as IR photons, with wavelengths near the ones used in data communication. This discovery was the starting point for the team’s approach to constructing qubits.