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arXiv · 0803.0470

Feedback cooling of the normal modes of a massive electromechanical system to submillikelvin temperature

A. Vinante·M. Bignotto·M. Bonaldi·M. Cerdonio·L. Conti·P. Falferi·N. Liguori·S. Longo·R. Mezzena·A. Ortolan·G. A. Prodi·F. Salemi·L. Taffarello·G. Vedovato·S. Vitale·J. -P. Zendri
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Abstract

We apply a feedback cooling technique to simultaneously cool the three electromechanical normal modes of the ton-scale resonant-bar gravitational wave detector AURIGA. The measuring system is based on a dc Superconducting Quantum Interference Device (SQUID) amplifier, and the feedback cooling is applied electronically to the input circuit of the SQUID. Starting from a bath temperature of 4.2 K, we achieve a minimum temperature of 0.17 mK for the coolest normal mode. The same technique, implemented in a dedicated experiment at subkelvin bath temperature and with a quantum limited SQUID, could allow to approach the quantum ground state of a kilogram-scale mechanical resonator.

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A. Vinante, M. Bignotto, M. Bonaldi, M. Cerdonio, L. Conti, P. Falferi, N. Liguori, S. Longo, R. Mezzena, A. Ortolan, G. A. Prodi, F. Salemi, L. Taffarello, G. Vedovato, S. Vitale, J. -P. Zendri. 2008-09-18. Feedback cooling of the normal modes of a massive electromechanical system to submillikelvin temperature. https://doi.org/10.1103/physrevlett.101.033601

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