The quantum Hall (QH) effect in two-dimensional electron systems (2DESs) is conventionally observed at liquid-helium temperatures, where lattice vibrations are strongly suppressed and bulk carrier scattering is dominated by disorder. However, due to large Landau level (LL) separation (~2000 K at B = 30 T), graphene can support the QH effect up to room temperature (RT), concomitant with a non-negligible population of acoustic phonons with a wave-vector commensurate to the inverse electronic magnetic length. Here, we demonstrate that graphene encapsulated in hexagonal boron nitride (hBN) realizes a novel transport regime, where dissipation in the QH phase is governed predominantly by electron-phonon scattering.
View Article and Find Full Text PDFThe nature of the low-frequency 1/ noise in electronic materials and devices is one of the oldest unsolved physical problems ( is the frequency). The fundamental question of the noise source-fluctuations in the mobility . number of charge carriers-is still debated.
View Article and Find Full Text PDFWe report on the enhancement of responsivity by more than one order of magnitude of a silicon-based sub-terahertz detector when a mesoscopic dielectric particle was used to localize incident radiation to a sub-wavelength volume and focus it directly onto the detector. A strained-silicon modulation field-effect transistor was used as a direct detector on an incident terahertz beam at 0.3 THz.
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