Related papers: Nematic state in CeAuSb$_{2}$
We use Monte Carlo simulations and analytical arguments to analyze a frustrated Ising model with nearest neighbour antiferromagnetic coupling $J_1$ and next nearest neighbour coupling $J_2$. The model is inspired on the physics of pnictide…
We report on optical measurements of the 1D Heisenberg antiferromagnet KCuF3. The crystal-field excitations of the Cu2+ ions have been observed and their temperature dependence can be understood in terms of magnetic and exchange-induced…
Thermal expansion, magnetostriction and magnetization measurements under magnetic field and hydrostatic pressure were performed on a $\mathrm{UAu_{2}Si_{2}}$ single crystal. They revealed a large anisotropy of magnetoelastic properties…
We report on $^{75}$As-NMR measurements in single crystalline BaFe$_{2}$(As$_{0.96}$P$_{0.04}$)$_{2}$ for magnetic fields parallel to the orthorhombic $[110]_{\rm o}$ and $[100]_{\rm o}$ directions above the structural transition…
A technique for measuring the electrical resistivity and absolute thermopower is presented for pressures up to 30 GPa, temperatures down to 25 mK and magnetic fields up to 10 T. With the examples of CeCu2Ge2 and CeCu2Si2 we focus on the…
The effect of quantum and thermal fluctuations on the phase diagram of spin-2 BECs is examined. They are found to play an important role in the nematic part of the phase diagram, where a mean-field treatment of two-body interactions is…
In copper-oxide and iron-based high temperature (high-$T_{\rm c}$) superconductors, many physical properties exhibit in-plane anisotropy, which is believed to be caused by a rotational symmetry-breaking nematic order, whose origin and its…
Understanding the nature of the electronic nematic phase in iron pnictide superconductors is important for elucidating its impact on high-temperature superconductivity. Here we use transport and inelastic neutron scattering to study spin…
Contrary to prior calculations, the Ni-rich ordered structures of the Cr-Ni alloy system are found to be antiferromagnetic under semi-local density-functional theory. The optimization of local magnetic moments significantly increases the…
The tetragonal heavy fermion compound CeRh2As2 exhibits unconventional superconductivity accompanied by other broken symmetry phases that have been identified as presumably small moment intrinsic antiferromagnetism at low magnetic fields…
In several Fe-based superconductors, slight $C_4$ symmetry breaking occurs at $T^*$, which is tens of Kelvin higher than the structural transition temperature $T_S$. In this "hidden" nematic state at $T_S<T<T^*$, the orthorhombicity is tiny…
The nature of the antiferromagnetic order in the heavy fermion metal YbRh$_2$Si$_2$, its quantum criticality, and superconductivity, which appears at low mK temperatures, remain open questions. We report measurements of the heat capacity…
The phase diagram of iron-based superconductors contains a host of electronic orders, which are intimately connected with their superconductivity. Here we analyze the fluctuations of one type of nematic order in another. Our analysis leads…
Overshadowing the superconducting dome in hole-doped cuprates, the pseudogap state is still one of the mysteries that no consensus can be achieved. It has been suggested that the rotational symmetry is broken in this state and may result in…
We have investigated the magnetic properties of a non-symmorphic correlated material, TbAgSb2. It consists of a quasi-two-dimensional structure of Sb atoms which hosts topologically non-trivial fermions. We prepared high quality single…
The phase transition to ferromagnetic order in itinerant ferromagnetic superconductor UGe$_2$ as function of pressure shows change of phase transition order. At low temperature and high pressure the transition is of first order and at…
A nematic topological superconductor has an order parameter symmetry, which spontaneously breaks the crystalline symmetry in its superconducting state. This state can be observed, for example, by thermodynamic or upper critical field…
Motivated by recent observation of a new high field phase near saturation in chromium spinels $A$Cr$_2$O$_4$ ($A=$ Zn, Cd, Hg), we study the $S = 3/2$ pyrochlore Heisenberg antiferromagnet with biquadratic interactions. Magnon instability…
We report Cu nuclear-quadrupole-resonance results under pressure on a homogeneous CeCu2Si2 (Tc = 0.65 K) that revealed critical magnetic fluctuations at the border to an antiferromagnetic phase. This exotic superconducting phase evolves…
Magnetic interactions are generally believed to play a key role in mediating electron pairing for superconductivity in iron arsenides; yet their character is only partially understood. Experimentally, the antiferromagnetic (AF) transition…