Signature of Many-Body Localization of Phonons in Strongly Disordered Superlattices.

Autor: Nguyen T; Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Andrejevic N; Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Po HC; Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Song Q; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Tsurimaki Y; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States., Drucker NC; John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States., Alatas A; Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States., Alp EE; Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States., Leu BM; Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States.; Department of Physics, Miami University, Oxford, Ohio 45056, United States., Cunsolo A; Department of Physics, University of Wisconsin at Madison, Madison, Wisconsin 53706, United States., Cai YQ; National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States., Wu L; Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States., Garlow JA; Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States., Zhu Y; Condensed Matter Physics and Material Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States., Lu H; College of Engineering and Applied Sciences, Nanjing University, Nanjing, China., Gossard AC; Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States., Puretzky AA; Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Geohegan DB; Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States., Huang S; Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Li M; Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Jazyk: angličtina
Zdroj: Nano letters [Nano Lett] 2021 Sep 08; Vol. 21 (17), pp. 7419-7425. Date of Electronic Publication: 2021 Jul 27.
DOI: 10.1021/acs.nanolett.1c01905
Abstrakt: Many-body localization (MBL) has attracted significant attention because of its immunity to thermalization, role in logarithmic entanglement entropy growth, and opportunities to reach exotic quantum orders. However, experimental realization of MBL in solid-state systems has remained challenging. Here, we report evidence of a possible phonon MBL phase in disordered GaAs/AlAs superlattices. Through grazing-incidence inelastic X-ray scattering, we observe a strong deviation of the phonon population from equilibrium in samples doped with ErAs nanodots at low temperature, signaling a departure from thermalization. This behavior occurs within finite phonon energy and wavevector windows, suggesting a localization-thermalization crossover. We support our observation by proposing a theoretical model for the effective phonon Hamiltonian in disordered superlattices, and showing that it can be mapped exactly to a disordered 1D Bose-Hubbard model with a known MBL phase. Our work provides momentum-resolved experimental evidence of phonon localization, extending the scope of MBL to disordered solid-state systems.
Databáze: MEDLINE