【IMPORTANT】T2R2 and STAR Search: Service Discontinuation and Successor Systems Japanese

Home > Help Publication Information Title Japanese:   English: Refined Sensitivity Estimates for Single-Molecule Magnet Dark Matter Detectors  Author Japanese: Andrew Eberhardt, 福井 智也, 竹原 陵介, Ryotaro Ohno, Yuta Mizukami, Kenichiro Hashimoto, 福島 孝典, Shigeki Matsumoto, Tom Melia, Kouki Nozaki, Surjeet Rajendran.   English: Andrew Eberhardt, Tomoya Fukui, Ryosuke Takehara, Ryotaro Ohno, Yuta Mizukami, Kenichiro Hashimoto, Takanori Fukushima, Shigeki Matsumoto, Tom Melia, Kouki Nozaki, Surjeet Rajendran.   Language English  Journal/Book name Japanese:   English: arXiv:2607.01868  Volume, Number, Page         Published date July 2, 2026  Publisher Japanese:   English:   Conference name Japanese:   English:   Conference site Japanese:   English:   Official URL https://arxiv.org/abs/2607.01868   DOI https://doi.org/10.48550/arXiv.2607.01868 Abstract We revisit the sensitivity of Single Molecule Magnet (SMM) crystals as detectors for low-mass dark matter. In previous work, we established the concept of the ``magnetic bubble chamber'', where energy deposited by dark matter triggers a magnetic avalanche in a metastable crystal. The original sensitivity estimates relied on a conservative criterion requiring the spin relaxation time to be strictly shorter than the thermal diffusion time. Here, we demonstrate that this criterion effectively ignores the stochastic nature of spin relaxation. We derive a refined analytic estimate which accounts for the fraction of spins that relax even when diffusion is fast. We show that the Zeeman energy released by this fraction contributes to local heating, significantly lowering the energy threshold for avalanche formation. We present simulation results confirming this effect and report on experimental verification of the assumed low-temperature thermal properties of two representative SMM crystals, Mn12-acetate and Mn32. Together, these efforts extend this pathfinder program toward the realization of SMM-based detectors with controlled material properties and enhanced dark matter sensitivity.

©2007 Institute of Science Tokyo All rights reserved.