Characterizing TES Power Noise for Future Single Optical-Phonon and Infrared-Photon Detectors

Abstract

In this letter, we present the performance of a $100\hat{I}¼\mathrm{m}\times 400\hat{I}¼\mathrm{m}\times 40\mathrm{nm}$ tungsten (W) Transition-Edge Sensor (TES) with a critical temperature of 40 mK. This device has a measured noise equivalent power (NEP) of $1.5\times 10^{-18}\mathrm{W}/\sqrt{\mathrm{Hz}}$, in a bandwidth of $2.6$ kHz, indicating a resolution for Dirac delta energy depositions of $40\pm 5\mathrm{meV}$ (rms). The performance demonstrated by this device is a critical step towards developing a $\mathcal{O}(100)\mathrm{meV}$ threshold athermal phonon detectors for low-mass dark matter searches.

5 pages, 6 figures. Accepted for publication at AIP Advances