DIELECTRIC RESPONSE OF 2-LEVEL SYSTEMS TO STRAIN FIELDS AT LOW-TEMPERATURES

Recent experiments at low temperatures in amorphous insulators have st udied ac dielectric response to the rapid application of a de electric field. We are performing a similar experiment, measuring epsilon'(ome ga,T) Of an amorphous insulator while applying a uniform elastic strai n, at temperatures both above and below the minimum of epsilon'(omega, T). Measurements of delta epsilon' in response to sudden and slowly va rying strain are reported. Preliminary results show a depressed epsilo n' response around zero strain, similar to that seen previously near z ero bias electric field, which becomes shallower with increasing T. We discuss frequency dependence of this response, as well as future work .