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Spin excitations in the antiferromagnetic Néel phase of the Shastry-Sutherland crystal SrCu2(BO3)2 have been investigated using inelastic neutron scattering. No clear excitations could be identified, possibly due to challenging experimental conditions ulti ...
We consider a model of sub-GeV dark matter whose interaction with the Standard Model is mediated by a new vector boson (the dark photon) which couples kinetically to the photon. We describe the possibility of constraining such a model using a superfluid He ...
We model interactions following the Sachdev-Ye-Kitaev (SYK) framework in disordered graphene flakes up to 300 000 atoms in size (-100 nm in diameter) subjected to an out-of-plane magnetic field B of 5-20 Tesla within the tight-binding formalism. We investi ...
We present a microscopic theory of heat and particle transport of an interacting, low-temperature Bose- Einstein condensate in a quantum point contact.We show that, in contrast to charged, fermionic superconductors, bosonic systems feature tunneling proces ...
The possibility for helium-induced electronic transitions in a photo-excited atom is investigated using Ba+ excited to the 6p 2P state as a prototypical example. A diabatization scheme has been designed to obtain the necessary potential energy surfaces and ...
We study the response of a He-4 detector to the interaction of sub-GeV dark matter using an effective field theory for the superfluid. We compute the lifetime of the phonon, which agrees with what known from standard techniques, hence providing an importan ...
The interaction between coherent polaritons and incoherent excitons plays an important role in polariton physics. Using resonant pump-probe spectroscopy with selective excitation of single polariton branches, we investigate the different dephasing mechanis ...
We employ an effective field theory to study the detectability of sub-GeV dark matter through its interaction with the gapless excitations of superfluid 4He. In a quantum field theory language, the possible interactions between the dark matter and the supe ...
Microcavity polaritons are hybrid quasiparticles emerging from the strong coupling between quantum well excitons and light in the resonator. Their unique half-light half-matter nature brings in specific properties like low effective mass, nonlinearity due ...
We show how a relativistic effective field theory for the superfluid phase of 4 He can replace the standard methods used to compute the production rates of low-momentum excitations due to the interaction with an external probe. This is done by studying the ...