Calorimetric Observation of Single \(\hbox {He}_2^*\) Excimers in a 100-mK He Bath

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• 作者：F. W. Carter ; S. A. Hertel ; M. J. Rooks…
• 关键词：Helium excimer detection ; Superconducting detector ; Transition edge sensor ; Superfluid helium
• 刊名：Journal of Low Temperature Physics
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：186
• 期：3-4
• 页码：183-196
• 全文大小：1331KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Condensed Matter Physics; Characterization and Evaluation of Materials; Magnetism, Magnetic Materials;
• 出版者：Springer US
• ISSN：1573-7357
• 卷排序：186

文摘

We report the first calorimetric detection of individual \(\hbox {He}_2^*\) excimers within a bath of superfluid \(^4\hbox {He}\). The detector used in this work is a single superconducting titanium transition edge sensor (TES) with an energy resolution of \({\sim }1~\hbox {eV}\), immersed directly in the helium bath. \(\hbox {He}_2^*\) 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 (and discrimination) of both states: In the singlet case the calorimeter records the absorption of a prompt \({\approx }15~\hbox {eV}\) 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 \({\approx }15~\hbox {eV}\), released upon decay, into the surface. We also briefly discuss the detector fabrication and characterization.