Current news

New publication in Phys. Rev. X and Highlight in this weeks Physics Magazine: Frequency comb from a single driven nonlinear nanomechanical mode

Phononic frequency combs have attracted increasing attention both as a qualitatively new type of nonlinear phenomena in vibrational systems and from the point of view of applications. It is commonly believed that at least two modes must be involved in generating a comb. We demonstrate that a comb can be generated by a single nanomechanical mode driven by a resonant monochromatic drive. The comb emerges where the drive is still weak, so the anharmonic part of the mode potential energy remains…

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New Publication in Phys. Rev. B: Thermal conductance and noise of Majorana modes along interfaced ν=5/2 fractional quantum Hall states

Identifying the topological order of the fractional quantum Hall state at filling v=5/2 is an important step towards realizing non-Abelian Majorana modes in condensed matter physics. However, to unambiguously distinguish between various proposals for this order is a formidable challenge. Here, we present a detailed study of transport along interfaced edge segments of fractional quantum Hall states hosting non-Abelian Majorana modes. With an incoherent model approach, we compute, for edge…

New Publication in Physics. Rev. B: Light emission in delta-T-driven mesoscopic conductors

The scattering picture of electron transport in mesoscopic conductors shows that fluctuations of the current reveal additional information on the scattering mechanism not available through the conductance alone. The electronic fluctuations are coupled to the electromagnetic field and a junction at finite bias or temperature will emit radiation. The nonsymmetrized current-current correlators characterize the emission and absorption spectrum. Recent interest is focused on the so-called…

New publication in Physical Review Letters: Measurements of Phase Dynamics in Planar Josephson Junctions and SQUIDs

We experimentally investigate the stochastic phase dynamics of planar Josephson junctions (JJs) and superconducting quantum interference devices (SQUIDs) defined in epitaxial InAs/Al heterostructures, and characterized by a large ratio of Josephson energy to charging energy. We observe a crossover from a regime of macroscopic quantum tunneling to one of phase diffusion as a function of temperature, where the transition temperature T* is gate-tunable. The switching probability distributions are…

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