相关论文: Covalent bonding and magnetism in cuprates
Beyond 14GPa of pressure, bi-layered La$_3$Ni$_2$O$_7$ was recently found to develop strong superconductivity above the liquid nitrogen boiling temperature. An immediate essential question is the pressure-induced qualitative change of…
Disorder can have remarkably disparate consequences in superconductors, driving superconductor-insulator transitions in ultrathin films by localizing electron pairs and boosting the supercurrent carrying capacity of thick films by…
Understanding the effects of electron-electron interactions in half metallic magnets (HMs), which have band structures with one gapped spin channel and one metallic channel, poses fundamental theoretical issues as well as having importance…
Despite intense efforts during the last 25 years, the physics of unconventional superconductors, including the cuprates with a very high transition temperature, is still a controversial subject. It is believed that superconductivity in many…
Magnetic superconductors manifest a fascinating interplay between their magnetic and superconducting properties. This becomes evident, for example, in the significant enhancement of the upper critical field observed in uranium-based…
We present a comparative study of magnetic excitations in the first two Ruddlesden-Popper members of the Hg-family of high-temperature superconducting cuprates, which are chemically nearly identical and have the highest critical temperature…
We study the triangular antiferromagnet Cu$_3$ in external electric fields, using symmetry group arguments and a Hubbard model approach. We identify a spin-electric coupling caused by an interplay between spin exchange, spin-orbit…
The three dimensional periodic Anderson model is studied with Quantum Monte Carlo. We find that the cross-over to the Kondo singlet regime is remarkably sharp at low temperatures, and that the behavior of magnetic correlations is…
There exists increasing evidence that the phase diagram of the high-transition temperature (Tc) cuprate superconductors is controlled by a quantum critical point. One distinct theoretical proposal is that, with decreasing hole-carrier…
Heterostructures consisting of a cuprate superconductor YBa2Cu3O7x and a ruthenate/manganite (SrRuO3/La0.7Sr0.3MnO3) spin valve have been studied by SQUID magnetometry, ferromagnetic resonances and neutron reflectometry. It was shown that…
There are two interpretations offered for the different structural and magnetic properties of the mixed valence homo-metallic ludwigites, Co3O2BO3 and Fe3O2BO3. One of them associates the physical behavior to charge ordering processes among…
The microscopic origin of metamagnetism and metamagnetic transitions in strongly anisotropic antiferromagnets is investigated within a quantum mechanical theory of correlated electrons. To this end the Hubbard model with staggered…
The high-temperature superconductivity in copper oxides emerges under strong influence of spin correlations in doped Mott insulators. Recent discoveries of charge-order (CO) correlations in Y-based hole-doped cuprates as well as in…
Multilayered cuprates possess not only the highest superconducting temperature transition but also offer a unique platform to study disorder-free CuO$_2$ planes and the interplay between competing orders with superconductivity. Here, we…
The Hubbard model is believed to capture the essential physics of cuprate superconductors. However, recent theoretical studies suggest that it fails to reproduce a robust and homogeneous superconducting ground state. Here, using resonant…
I propose that a dopant charge singlet bonding state may arise from the hybridization of molecular orbitals in a cluster containing 13 Cu atoms in the CuO2 plane of the superconducting cuprates. This singlet state forms a pre-formed pair…
Unlike ordinary conductors and semiconductors, which conduct electricity through individual electrons, superconductors usually conduct electricity through electron pairs, known as Cooper pairs. Even after 4 decades of intense study, no one…
We show that the interplay of strong Hubbard interaction $U$ and spin-orbit coupling $\lambda$ in systems with $d^4$ electronic configuration leads to several unusual magnetic phases. Most notably, we find that competition between…
Motivated by recent experimental studies on superconductivity found in nickelate-based materials, we study the temperature dependence of the spin correlation and the superconducting pairing interaction within an effective two-band Hubbard…
A brief history is offered concerning the relation of magnetism to superconductivity, and the possibility that magnetic correlations are responsible for certain types of superconductors. A central focus is on high temperature cuprate…