CTQM Theory Colloquium

First Laboratory Bounds on Ultralight Dark Photon Dark Matter from Precision Atomic Spectroscopy

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Abstract: Ultralight bosonic dark matter has come under increasing scrutiny as a dark matter candidate that has the potential to resolve puzzles in astronomical observation. I demonstrate that high-precision measurements of time variation in the frequency ratios of atomic transitions achieve leading sensitivity to ultralight vector portal dark matter at low masses. These bounds are the first laboratory-based bounds on this class of dark matter models. I discuss further measurements that could enhance sensitivity to ultralight dark photons.

 

Nonabelian Hall conductance in general dimensions as an invariant of the interacting ground state wavefunction

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Abstract: The long-wavelength response of a gapped many-body system in D spatial dimensions with a Lie group symmetry G to an external gauge field is believed to be described by a Chern-Simons action in dimension D+1. Since the coefficient of the Chern-Simons action is quantized, it is a topological invariant (i.e. is unchanged under deformations of the Hamiltonian which do not close the gap).

Relativistic Wind Farm Effect: Possibly Turbulent Flow of a Charged, Massless Relativistic Fluid in Graphene

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Abstract: At low Reynolds numbers, the wind flow in the wake of a single wind turbine is generally not turbulent. However, turbines in wind farms affect each other’s wakes so that a turbulent flow can arise. In the present work, an analogue of this effect for the massless charge carrier flow around obstacles in graphene is outlined.

Electrical probes of non-Abelian spin liquids

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Abstract: Recent thermal-conductivity measurements evidence a magnetic-field-induced non-Abelian spin liquid phase in the Kitaev material α-RuCl3. In this talk, I will explain how we leverage fermion condensation to propose a series of measurements for electrically detecting the hallmark chiral Majorana edge states and bulk anyons in the spin-liquid phase -- despite the fact that α-RuCl3 is a good Mott insulator.