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Study of the mechanical loss of amorphous mirror coatings for gravitational wave detectors using two level system model

ORAL

Abstract

For future generation of laser interferometer gravitational-wave observatory (LIGO), thermal noise from amorphous mirror coatings will be a limiting noise source in the most-sensitive frequency band (about 150 Hz).[CQG 25.11,114041] In our previous studies, two level system (TLS) model was used to study the mechanical loss of the pure and doped amorphous SiO2, Ta2O5 coatings.[JCP 141.5,054501, PRB 93.1,014105, PRB 95.1,014109] With reverse Monte Carlo (RMC) method, we generate amorphous models for both as-deposited and heat treated samples based on measurements of grazing-incidence pair distribution function (GIPDF).[PRL 123.4,045501] In this work, we further refine the RMC models of 50% ZrO2 doped Ta2O5 with first-principles atomic structure relaxation and improve the previous TLS model by correctly taking into account two relaxation times associated with one asymmetrical TLS transition. From the mechanical loss calculation based on these models, we find that annealing will partially eliminate voids (or pores) larger than 200 A3 and smaller than 100 A3 making the atomic structures more uniform, which is correlated with high mechanical loss at low temperature.

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Presenters

  • Jun Jiang

    Department of Physics and Quantum Theory Project, University of Florida, University of Florida, Department of Physics, Center for Molecular Magnetic Quantum Materials and Quantum Theory Project, University of Florida, Physics, University of Florida

Authors

  • Jun Jiang

    Department of Physics and Quantum Theory Project, University of Florida, University of Florida, Department of Physics, Center for Molecular Magnetic Quantum Materials and Quantum Theory Project, University of Florida, Physics, University of Florida

  • Alec Mishkin

    Department of Physics and Quantum Theory Project, University of Florida, University of Florida, Physics, University of Florida

  • Kiran Prasai

    E. L. Ginzton Laboratory, Stanford University, Stanford University, E.L. Ginzton Laboratory, Stanford University

  • Riccardo Bassiri

    E. L. Ginzton Laboratory, Stanford University, Stanford University, Department of Applied Physics, Ginzton Laboratory, Stanford University, Edward L. Ginzton Laboratory, Stanford University, E.L. Ginzton Laboratory, Stanford University

  • Martin M. Fejer

    E. L. Ginzton Laboratory, Stanford University, Stanford University, Department of Applied Physics, Ginzton Laboratory, Stanford University, Edward L. Ginzton Laboratory, Stanford University, E.L. Ginzton Laboratory, Stanford University

  • Hai-Ping Cheng

    University of Florida, Department of Physics, Center for Molecular Magnetic Quantum Materials and Quantum Theory Project, University of Florida, Department of Physics and Quantum Theory Project, University of Florida, Physics, Univrsity of FL, Physics, University of Florida