Figure 1: Microwave spectroscopy of wide quantum wells.
From: Microwave spectroscopic observation of distinct electron solid phases in wide quantum wells
(a) Left: sketch of carriers (black) of an electron solid within the residual disorder potential, which is shown by colour (not to scale). Right: a piece (domain) of solid moves within a potential due to the disorder averaged over the domain, giving rise to the pinning mode studied here. (b) Schematic of the microwave set-up. The source and detector are at room temperature. A CPW transmission line is patterned on the top surface of the sample, with metal film of the CPW shown in black. (c) Side view of the sample (not to scale) shows the placement of the front and back gates and the metal film of the CPW. Slots of width s separate the centre conductor and ground planes of the CPW. (d,e) Spectra (diagonal conductivity Re(σxx) versus frequency f) obtained from the 54 nm well with n=1.95 and 2.53, at several v*=v−1, marked on the right axis of g. Successive spectra are offset upward by 1 μS in d and 2 μS in e. (f,g) Spectra for the 65 nm well at n=1.39 and 1.93 offset consecutively by 1 μS. For each spectrum the magnetic field, B, at v=1 is marked.
