Interaction of two level systems in amorphous materials with arbitrary phonon fields.
To describe the interaction of the two-level systems (TLSs) of an amorphous solid with arbitrary strain fields, we introduce a generalization of the standard interaction Hamiltonian. In this model, the interaction strength depends on the orientation of the TLS with respect to the strain field through a 6 x 6 symmetric tensor of deformation potential parameters [R]. Taking into account the isotropy of the amorphous solid, we deduce that [R] has only two independent parameters. We show how these two parameters can be calculated from experimental data, and we prove that for any amorphous bulk material, the average coupling of TLSs with longitudinal phonons is always stronger than the average coupling with transversal phonons (in standard notations, {gamma}{sub l} > {gamma}{sub t}).
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); NATO
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 940700
- Report Number(s):
- ANL/MSD/JA-57783; TRN: US0807188
- Journal Information:
- Phys. Rev. B, Vol. 75, Issue 2007; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- ENGLISH
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