Concept

Universality class

Publications associées (30)

Dimensional Reduction in Quantum Dipolar Antiferromagnets

Henrik Moodysson Rønnow, Martin Mansson, Peter Babkevich, Ivan Kovacevic

We report ac susceptibility, specific heat, and neutron scattering measurements on a dipolar-coupled antiferromagnet LiYbF4. For the thermal transition, the order-parameter critical exponent is found to be 0.20(1) and the specific-heat critical exponent -0 ...

2016

Dimerization transitions in spin-1 chains

Frédéric Mila, Natalia Chepiga

We study spontaneous dimerization transitions in a Heisenberg spin-1 chain with additional next-nearest-neighbor and three-site interactions using extensive numerical simulations and a conformal field-theory analysis. We show that the transition can be sec ...

2016

Spontaneous dimerization, critical lines, and short-range correlations in a frustrated spin-1 chain

Frédéric Mila, Natalia Chepiga

We report on a detailed investigation of the spin-1 J1−J2−J3 Heisenberg model, a frustrated model with nearest-neighbor coupling J1, next-nearest neighbor coupling J2, and a three-site interaction J3[(Si−1⋅Si)(Si⋅Si+1)+H.c.] previously studied in [Phys. Re ...

2016

Exact diagonalization of HeisenbergSU(N)chains in the fully symmetric and antisymmetric representations

Frédéric Mila, Pierre Marcel Nataf

Motivated by recent experimental progress in the context of ultracold multicolor fermionic atoms in optical lattices, we have developed a method to exactly diagonalize the Heisenberg SU(N) Hamiltonian with several particles per site living in a fully symme ...

2016

Single crystals of superconducting SmFeAsOHx: Structure and properties

László Forró, Alla Arakcheeva, Richard Gaal, Sergiy Katrych, Andrea Pisoni, Ping Huang, Péter Krisztián Matus

We report the synthesis, structure, and superconducting properties of single crystals of SmFeAsOHx. The crystals were grown at high pressure and high temperature using a cubic anvil technique. H-1-NMR studies confirm the presence of H atoms in the samples. ...

Amer Physical Soc2016

Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm4Fe2As2Te1-xO4-yFy

László Forró, Bálint Náfrádi, Richard Gaal, Sergiy Katrych, Péter Szirmai, Andrea Pisoni

We present a detailed study of the electrical transport properties of a recently discovered iron-based superconductor: Sm4Fe2As2Te0.72O2.8F1.2. We followed the temperature dependence of the upper critical field by resistivity measurement of single crystals ...

Iop Publishing Ltd2016

Importance of XY anisotropy in Sr2IrO4 revealed by magnetic critical scattering experiments

Henrik Moodysson Rønnow

The magnetic critical scattering in Sr2IrO4 has been characterized using x-ray resonant magnetic scattering (XRMS) both below and above the three-dimensional antiferromagnetic ordering temperature T-N. The order parameter critical exponent below TN is foun ...

2015

The role of fluctuations in ecological patterns and processes

Andrea Giometto

Fluctuations are ubiquitous in nature and are relevant for nearly every ecological process. The main sources of fluctuations in population abundances are demographic and environmental stochasticity, whose effect on local population dynamics, metapopulation ...

EPFL2015

How colloid-colloid interactions and hydrodynamic effects influence the percolation threshold: A simulation study in alumina suspensions

Paul Bowen

The percolation behavior of alumina suspensions is studied by computer simulations. The percolation threshold phi(c), is calculated, determining the key factors that affect its magnitude: the strength of colloid-colloid attraction and the presence of hydro ...

Elsevier2015

Nonlinear Midinfrared Photothermal Spectroscopy Using Zharov Splitting and Quantum Cascade Lasers

Hatice Altug

We report on the Mid-infrared nonlinear photothermal spectrum of the neat liquid crystal 4-octyl-4'-cyanobiphenyl (8CB) using a tunable Quantum Cascade Laser (QCL). The nonequilibrium steady state characterized by the nonlinear photothermal infrared respon ...

2014