Related papers: Chiral charge as hidden order parameter in URu$_2$…
Motivated by experiment, we argue that the enigmatic hidden order in $URu_2Si_2$ demands a dual description that encompasses both its itinerant and its local aspects. A combination of symmetry considerations and observation allow us to rule…
We propose that the "hidden order parameter" in URu$_2$Si$_2$ is a helicity order which must arise, if the Pomeranchuk criteria for the spin-antisymmetric Landau parameters with respect to the stability of a Fermi liquid state are violated.…
A second-order phase transition is associated with emergence of an "order parameter" and a spontaneous symmetry breaking. For the heavy fermion superconductor URu$_2$Si$_2$, the symmetry of the order parameter associated with its ordered…
The unusual correlated state that emerges in URu$_2$Si$_2$ below T$_{HO}$ = 17.5 K is known as "hidden order" because even basic characteristics of the order parameter, such as its dimensionality (whether it has one component or two), are…
It was recently discovered that in spite of the scalar nature of its order parameter, the charge order in 1T-TiSe2 can be chiral. This is made possible by the emergence of orbital order in conjunction with the charge density modulations.…
A systematic search for possible order parameters of the so-called hidden order of URu$_{2}$Si$_{2}$ is conducted. Among the possible candidates that do fulfill the experimental symmetry restrictions on the hidden order parameter, we find…
The relation between crystal symmetries, electron correlations, and electronic structure steers the formation of a large array of unconventional phases of matter, including magneto-electric loop currents and chiral magnetism. Detection of…
We review current attempts to characterize the underlying nature of the hidden order in $URu_2Si_2$. A wide variety of experiments point to the existence of two order parameters: a large primary order parameter of unknown character which…
We argue that key characteristics of the enigmatic transition at $T_0= 17.5K $ in $URu_2Si_2$ indicate that the hidden order is a density wave formed within a band of composite quasiparticles, whose detailed structure is determined by local…
We report the use of impurities to probe the hidden order parameter of the strongly correlated metal URu_2Si_2 below the transition temperature T_0 ~ 17.5 K. The nature of this order parameter has eluded researchers for more than two…
On the basis of group theory and the first-principles calculations, we investigate high-rank multipole orderings in URu2Si2, which have been proposed as a genuine primary order parameter in the hidden order phase below 17.5K. We apply…
Resonant elastic X-ray scattering is a powerful technique for measuring multipolar order parameters. In this paper, we theoretically and experimentally study the possibility of using this technique to detect the proposed multipolar order…
We show that the recently observed chirality in the charge ordered phase of TiSe2 can be understood as a form of orbital ordering. The microscopic mechanism driving the transition between the novel chiral state and the non-chiral charge…
We find chiral charge order in the superconductor 2H-TaS2 using Scanning Tunneling Microscopy and Spectroscopy (STM/S) at 0.1 K. Topographic images show hexagonal atomic lattice and charge density wave (CDW) with clockwise and…
The low temperature hidden order state of URu$_2$Si$_2$ has long been a subject of intense speculation, and is thought to represent an as yet undetermined many-body quantum state not realized by other known materials. Here, X-ray absorption…
The hidden order phase of URu$_2$Si$_2$ has eluded identification for over thirty-five years. A compelling proposal that explains the Ising heavy-fermion nature of the material is \emph{hastatic order}: a symmetry breaking heavy-Fermi…
The hidden order phase in URu$_2$Si$_2$ is highly sensitive to electronic doping. A special interest in silicon-to-phosphorus substitution is due to the fact that it may allow one, in part, to isolate the effects of tuning the chemical…
In solid state physics, any symmetry breaking is known to be associated with emergence of an order parameter. However, the order parameter for molecular and crystal chirality, which is a consequence of parity and mirror symmetry breaking,…
Despite more than a quarter century of research, the nature of the second-order phase transition in the heavy-fermion metal URu$_2$Si$_2$ remains enigmatic. The key question is which symmetry is being broken below this "hidden order"…
I study the scalar representations of the electroweak group of the Standard Model, which is a subgroup of the chiral group U(N)L x U(N)R with N flavours, for N even, with a special emphasis on their chiral properties and on their behaviour…