相关论文: No Evidence for Orbital Loop Currents in Charge Or…
Intra-unit cell magnetic order has been observed in four different families of high-temperature superconductors from polarized neutron diffraction experiments and supported by several other techniques. That order, which does not break…
One of the leading issues in high-$T_C$ superconductors is the origin of the pseudogap phase in underdoped cuprates. Using polarized elastic neutron diffraction, we identify a novel magnetic order in the YBa$_2$Cu$_3$O$_{6+x}$ system. The…
The existence of the mysterious pseudo-gap state in the phase diagram of copper oxide superconductors and its interplay with unconventional {\it d-wave} superconductivity has been a long standing issue for more than a decade. There is now a…
The loop-current state discovered in under-doped cuprates is characterized by a vector ${\bf \Omega}$ which has four possible orientations which correspond to different domains of order in a perfect sample. Since translational symmetry…
Orbital current order of the d-density-wave type (DDW) has been postulated to explain the pseudogap in the high temperature superconductors. We have performed neutron scattering experiments to search for this order and show here the results…
The elucidation of the pseudogap phenomenon of the cuprates, a set of anomalous physical properties below the characteristic temperature T* and above the superconducting transition temperature Tc, has been a major challenge in condensed…
Understanding the pseudo-gap phase from which a superconducting state emerges is a central problem in the physics of cuprates. The phase exists below a temperature T* for less than optimal doping of holes, and no clear jump in the specific…
Polarized and unpolarized neutron diffraction has been used to search for magnetic order in YBa$_2$Cu$_3$O$_{6+x}$ superconductors. Most of the measurements were made on a high quality crystal of YBa$_2$Cu$_3$O$_{6.6}$. It is shown that…
Circulating current (CC) loops within the cuprate unit cell are proposed to play a key role in the physics of the pseudogap phase. However, main experimental observations motivated by this sophisticated proposal and seemingly supporting the…
Several decades of debate have centered around the nature of the enigmatic pseudo-gap state in high temperature superconducting copper oxides. Recently, we reported polarized neutron diffraction measurements that suggested the existence of…
We discuss the necessary symmetry conditions and the different ways in which they can be physically realized for the occurrence of ferromagnetism accompanying the loop current orbital magnetic order observed by polarized neutron-diffraction…
We report a polarized neutron scattering study of the orbital-like magnetic order in strongly underdoped ${\rm YBa_2Cu_3O_{6.45}}$ and ${\rm YBa_2(Cu_{0.98}Zn_{0.02})_3O_{6.6}}$. Their hole doping levels are located on both sides of the…
The issues raised in the preceding comment of Bourges et al. [arXiv:1710.08173, Phys. Rev. B 98, 016501 (2018)] are shown to be unfounded. We highlight the complications caused by inhomogeneous beam polarization that can occur when using…
We review the hallmarks of orbital loop currents in various correlated electron materials and how they have been evidenced using polarized neutron diffraction. Over the last 20 years, loop current signatures have been observed in high…
The theory of the long range order of orbital current loops in the pseudogap phase is generalized to include the effects of spin-orbit scattering. It is shown by symmetry arguments as well as by microscopic calculation that a specific…
We present muon spin relaxation (muSR) measurements on a large YBa2Cu3O6.6 single crystal in which two kinds of unusual magnetic order have been detected in the pseudogap region by neutron scattering. A comparison is made to measurements on…
Assuming, as suggested by recent neutron scattering experiments, that a broken symmetry state with orbital current order occurs in the pseudo-gap phase of the cuprate superconductors, we show that there must be associated equilibrium…
We present evidence for the existence of a spontaneous instability towards an orbital loop-current phase in a multiorbital Hubbard model for the CuO$_2$ planes in cuprates. Contrary to the previously proposed $\theta_{II}$ phase with…
The pseudogap phase of the cuprate superconductors is argued to be characterized by a hidden broken symmetry of d-wave character in the particle-hole channel that leads to staggered orbital magnetism. This proposal has many striking…
A symmetry-based interpretation of published experimental results demonstrates that the pseudo-gap phase of underdoped HgBa2CuO4(Hg1201) possesses an ordered state of magnetic charge epitomized by Cu magnetic monopoles. Magnetic properties…