Faster recovery time of a hot-electron transition-edge sensor by use of normal metal heat-sinks

Transition-edge sensor microcalorimeters with recovery times near 1 μs have become highly desirable in quantum science applications as near-infrared single-photon detectors with photon-number resolving capability. Previously, the recovery times of these devices could be decreased only by changing device material or modifying the superconducting-to-normal transition. We demonstrate a method for improving this speed that uses a normal-metal heat-sink. This demonstration with tungsten devices realizes a factor of 4 decrease in recovery time without significantly affecting energy resolution. Our approach may enable the creation of high-efficiency transition-edge sensors with decay times short enough to operate with 80 MHz pulsed single-photon sources.