Publications associées à Second sound

Characterization of two electronic subsystems in cuprates through optical conductivity

Ana Akrap, Edoardo Martino, Neven Barisic

Understanding the physical properties of unconventional superconductors as well as of other correlated materials presents a formidable challenge. Their unusual evolution with doping, frequency, and temperature has frequently led to non-Fermi-liquid (non-FL ...

2023

Many-body Green?s function approach to lattice thermal transport

Nicola Marzari, Michele Simoncelli

Recent progress in understanding thermal transport in complex crystals has highlighted the prominent role of heat conduction mediated by interband tunneling processes, which emerge between overlapping phonon bands (i.e., with energy differences smaller tha ...

AMER PHYSICAL SOC2022

Dark matter, dark photon and superfluid He-4 from effective field theory

Angelo Esposito, Emma Michèle Ginette Geoffray

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 ...

2020

Sub-GeV dark matter in superfluid He-4: an effective theory approach

Angelo Esposito

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 ...

Springer2019

Helium-induced electronic transitions in photo-excited Ba+–Hen exciplexes

Marcel Drabbels

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 ...

2018

Time-Reversal Symmetry Breaking in Re-Based Superconductors

Joël Mesot, Johan Juul Chang

To trace the origin of time-reversal symmetry breaking (TRSB) in Re-based superconductors, we performed comparative muon-spin rotation and relaxation (mu SR) studies of superconducting noncentrosymmetric Re0.82Nb0.18 (T-c = 8.8 K) and centrosymmetric Re (T ...

AMER PHYSICAL SOC2018

Nodeless superconductivity in the noncentrosymmetric Mo3Rh2N superconductor: A mu SR study

Joël Mesot

The noncentrosymmetric superconductor Mo3Rh2N, with T-c = 4.6 K, adopts a beta-Mn-type structure (space group P4(1)32), similar to that of Mo3Al2C. Its bulk superconductivity was characterized by magnetization and heat-capacity measurements, while its micr ...

AMER PHYSICAL SOC2018

Thermal transport in low dimensions

Andrea Cepellotti

Lattice vibrations are the microscopic mechanism responsible for a large, if not dominant, contribution to heat transport in crystalline insulators. These vibrations are described in terms of phonons, collective excitations (or quasiparticles) in the form ...

EPFL2016

Phonon hydrodynamics in two-dimensional materials

Nicola Marzari, Andrea Cepellotti, Giorgia Fugallo, Lorenzo Paulatto

The conduction of heat in two dimensions displays a wealth of fascinating phenomena of key relevance to the scientific understanding and technological applications of graphene and related materials. Here, we use density-functional perturbation theory and a ...

Nature Publishing Group2015

Magnetic field dependence of the basal-plane superconducting anisotropy in YBa2Cu4O8 from small-angle neutron scattering measurements of the vortex lattice

Joël Mesot, Jonathan White

We report a study of the basal-plane anisotropy of the superfluid density in underdoped YBa2Cu4O8 (Y124), showing the effects of both the CuO2 planes and the fully occupied CuO chains. From small-angle neutron scattering measurements of the vortex lattice, ...

American Physical Society2014

Conventional superconductivity and hysteretic Campbell penetration depth in single crystals MgCNi3

Sergiy Katrych

Single crystals of MgCNi3, with areas sized up to 1 mm(2), were grown by the self-flux method using a cubic anvil high-pressure technique. In low applied fields, the dc magnetization exhibited a very narrow transition into the superconducting state, demons ...

Amer Physical Soc2013

Semiclassical approach to ground-state properties of hard-core bosons in two dimensions

Frédéric Mila, Tommaso Coletta, Nicolas Laflorencie

Motivated by some inconsistencies in the way quantum fluctuations are included beyond the classical treatment of hard-core bosons on a lattice in the recent literature, we revisit the large-S semiclassical approach to hard-core bosons on the square lattice ...

2012

Polariton Superfluids Reveal Quantum Hydrodynamic Solitons

Romuald Houdré, Cristiano Ciuti

A quantum fluid passing an obstacle behaves differently from a classical one. When the flow is slow enough, the quantum gas enters a superfluid regime, and neither whirlpools nor waves form around the obstacle. For higher flow velocities, it has been predi ...

American Association for the Advancement of Science2011