Signature of Many-Body Localization of Phonons in Strongly Disordered Superlattices.
Nano Lett
; 21(17): 7419-7425, 2021 09 08.
Article
in En
| MEDLINE
| ID: mdl-34314183
ABSTRACT
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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phonons
/
Models, Theoretical
Language:
En
Journal:
Nano Lett
Year:
2021
Type:
Article
Affiliation country:
United States