Related papers: Chiral charge as hidden order parameter in URu$_2$…
The fundamental idea that the constituents of interacting many body systems in complex quantum materials may self-organise into long range order under highly non-equilibrium conditions leads to the notion that entirely new and unexpected…
We discuss the discovery of pressure-induced antiferromagnetism in URu_2Si_2, in the context of neutron, NMR and \mu SR results. The identification of a critical pressure separating mean-field and Ising phase transitions leads us to propose…
Since the discovery of charge disproportionation in the FeO$_2$ square-lattice compound Sr$_3$Fe$_2$O$_7$ by M\"ossbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained…
A lot of attention has been drawn to superconductivity in UTe$_2$, with suggestions of time-reversal symmetry breaking triplet chiral superconducting order parameter. The chirality of the order parameter has been attributed to an accidental…
The linear band crossings of 3D Dirac and Weyl semimetals are characterized by a charge chirality, the parallel or anti-parallel locking of electron spin to its momentum. Such materials are believed to exhibit a ${\bf E} \cdot {\bf B}$…
Chirality ubiquitously appears in nature, however, its quantification remains obscure owing to the lack of microscopic description at the quantum-mechanical level. We propose a way of evaluating chirality in terms of electric toroidal…
The heavy fermion compound URu$_2$Si$_2$ continues to attract great interest due to the unidentified hidden order it develops below 17.5K. The unique Ising character of the spin fluctuations and low temperature quasiparticles is well…
To resolve the nature of the hidden order below 17.5\,K in the heavy fermion compound URu$_2$Si$_2$, identifying which symmetries are broken below the hidden order transition is one of the most important steps. Several recent experiments on…
We develop a phenomenological mean field theory describing the hidden order phase in URu$_{\text2}$Si$_{\text2}$ as a nematic of the $\text B_{\text{1g}}$ representation staggered along the $c$-axis. Several experimental features are…
Quantum materials are epitomized by the influence of collective modes upon their macroscopic properties. Relatively few examples exist, however, whereby coherence of the ground-state wavefunction directly contributes to the conductivity.…
We discuss the conclusions on the symmetry of hidden order (HO) in URu2Si2 that may be drawn from recent torque experiments in rotating magnetic field by Okazaki et al. [1]. They are very sensitive to changes in the magnetic susceptibility…
Motivated by the co-existing charge and spin order found in strongly correlated ladder systems, we study an effective pseudospin model on a coupled two-leg ladder. A bosonisation analysis yields a rich phase diagram showing Wigner/Peierls…
We discuss predominant order parameters for structural chirality, and demonstrate that time-reversal-even axial-quadrupole plays a key role in stabilizing a chiral structure. Using the symmetry-adapted closest Wannier model of the trigonal…
An antiferro ordering of an electric hexadecapole moment is discussed as a promising candidate for the long standing mystery of the hidden order phase in URu$_{2}$Si$_{2}$. Based on localized $f$-electron picture, we discuss the rationale…
We examine recent magnetic torque measurements in two compounds, $\gamma$-Li$_2$IrO$_3$ and RuCl$_3$, which have been discussed as possible realizations of the Kitaev model. The analysis of the reported discontinuity in torque, as an…
Resonant soft x-ray scattering experiments with photon energies near the O K and the Cu L3 edge on the system La1.8-xEu0.2SrxCuO4 for 0.1 <= x <= 0.15 are presented. A phase diagram for stripe-like charge ordering is obtained together with…
The transition is studied by means of a disorder parameter detecting condensation of magnetic monopoles in the vacuum. The deconfining transition is found to coincide with the chiral transition and the susceptibility \rho, related to the…
Throughout the past three decades the hidden order (HO) problem in URu$_2$Si$_2$ has remained a "hot topic" in the physics of strongly correlated electron systems with well over 600 publications related to this subject. Presently in 2014…
Two of the most striking and yet unresolved manifestations of the hidden order (HO) in URu2Si2, are associated on one hand with the double-step metamagnetic transitions and on the other with the giant anomalous Nernst signal. Both are…
A phenomenological model for the 'hidden order' transition in the heavy Fermion material URu$_2$Si$_2$ is introduced. The 'hidden order' is identified as an incommensurate, momentum-carrying hybridization between the light hole band and the…