Thermal Detection Of Single E-H Pairs In A Biased Silicon Crystal Detector

We demonstrate that individual electron-hole pairs are resolved in a 1 cm(2) by 4mm thick silicon crystal (0.93 g) operated at similar to 35 mK. One side of the detector is patterned with two quasiparticle-trap-assisted electro-thermal-feedback transition edge sensor arrays held near ground potential. The other side contains a bias grid with 20% coverage. Bias potentials up to +/- 160V were used in the work reported here. A fiber optic provides 650 nm (1.9 eV) photons that each produce an electron-hole (e(-) h(+)) pair in the crystal near the grid. The energy of the drifting charges is measured with a phonon sensor noise sigma similar to 0.09 e h(-1) pair. The observed charge quantization is nearly identical for h(+)s or e(-)s transported across the crystal. Published by AIP Publishing.