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arXiv · 1605.00694

Calorimetric observation of single He2* excimers in a 100 mK He bath

F. W. Carter·S. A. Hertel·M. J. Rooks·P. V. E. McClintock·D. N. McKinsey·D. E. Prober
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Abstract

We report the first calorimetric detection of individual He2* excimers within a bath of superfluid 4He. The detector used in this work is a single superconducting titanium transition edge sensor (TES) with an energy resolution of ~1 eV, immersed directly in the helium bath. He2* excimers are produced in the surrounding bath using an external gamma-ray source. These excimers exist either as short-lived singlet or long-lived triplet states. We demonstrate detection of both states: in the singlet case the calorimeter records the absorption of a prompt 15 eV photon, and in the triplet case the calorimeter records a direct interaction of the molecule with the TES surface, which deposits a distinct fraction of the 15 eV, released upon decay, into the surface. We also briefly discuss the detector fabrication and characterization.

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F. W. Carter, S. A. Hertel, M. J. Rooks, P. V. E. McClintock, D. N. McKinsey, D. E. Prober. 2016-07-07. Calorimetric observation of single He2* excimers in a 100 mK He bath. https://doi.org/10.1007/s10909-016-1666-x

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