相关论文: Competition between covalent bonding and charge tr…
The superconductor-to-insulator transition (SIT) induced by means such as external magnetic fields, disorder or spatial confinement is a vivid illustration of a quantum phase transition dramatically affecting the superconducting order…
Considering the disorder caused in manganites by the substitution of Mn by Fe or Ga, we accomplish a systematic study of doped manganites begun in previous papers. To this end, a disordered model is formulated and solved using the…
The electronic properties of many transition metal oxide systems require new ideas concerning the behaviour of electrons in solids for their explanation. A recent example, subsequent to that of cuprate superconductors, is of rare earth…
We studied the magnetic properties of La$_{0.7}$Ca$_{0.3}$MnO$_3$ / YBa$_2$Cu$_3$O$_{7-\delta}$ superlattices. Magnetometry showed that with increasing YBa$_2$Cu$_3$O$_{7-\delta}$ layer thickness the saturation magnetization per…
In the manganites $RE_{1-x}AE_{x}$MnO$_{3}$ ($RE$ and $AE$ being rare-earth and alkaline-earth elements, respectively) the random distribution of $RE^{3+}$ and $AE^{2+}$ induces random, but correlated, shifts of site energies of charge…
A wide variety of experimental results and theoretical investigations in recent years have convincingly demonstrated that several transition metal oxides and other materials, have dominant states that are not spatially homogeneous. This…
Scaling relations in the charge and spin excitations of (La,Sr)MnO3 are studied from both theoretical and experimental points of view. In the ferromagnetic metal phase, we investigate optical conductivity and neutron inelastic scattering,…
The oxide interface SrTiO3/LaAlO3 supports a 2D electron liquid displaying superconductivity and magnetism, while allowing for a continuous control of the electron density using a gate. Our recent measurements have shown a similar…
The electronic properties of interfaces between two different solids can differ strikingly from those of the constituent materials. For instance, metallic conductivity, and even superconductivity, have been recently discovered at interfaces…
From a general model of the Mn oxides R_{1-x}A_{x}MnO_3, we derive an effective Hamiltonian in the low-energy subspace using the projection operator method, in which a novel coupling between the spin and orbital degrees of freedom is…
We present a thorough and quantitative comparison of double-exchange models to experimental data on the colossal magnetoresistance manganese perovskites. Our results settle a controversy by showing that physics beyond double-exchange is…
The physics of oxide superlattices is considered for pristine (001) multilayers of the band insulators LaAlO3 and SrTiO3 with alternating p and n interfaces. First principles results and a model of capacitor plates offer a simple paradigm…
Novel electronic systems forming at oxide interfaces comprise a class of new materials with a wide array of potential applications. A high mobility electron system forms at the LaAlO$_3$/SrTiO$_3$ interface and, strikingly, both…
The discovery of superconductivity in copper oxide compounds has attracted considerable attention over the past three decades. The high transition temperature in these compounds, exhibiting proximity to an antiferromagnetic order in their…
The ABO3 type charge-ordered antiferromagnetic Nd0.50Ca0.50MnO3 (NCMO) manganite is doped at A-site by 3 % of Ba2+ for Ca2+. The resulting system, Nd0.50Ca0.47Ba0.03MnO3 (NCBMO), is studied for the effects of Ba doping on the magnetic and…
The discovery of superconductivity in square-planar low valence nickelates has ignited a vigorous debate regarding their essential electronic properties: Do these materials have appreciable oxygen charge-transfer character akin to the…
Multilevel resistance states in silver-manganite interfaces are studied both experimentally and through a realistic model that includes as a main ingredient the oxygen vacancies diffusion under applied electric fields. The switching…
In pursuit of creating cuprate-like electronic and orbital structures, artificial heterostructures based on LaNiO$_3$ have inspired a wealth of exciting experimental and theoretical results. However, to date there is a very limited…
There are increasing indications that superconductivity competes with other orders in cuprate superconductors, but obtaining direct evidence with bulk-sensitive probes is challenging. We have used resonant soft x-ray scattering to identify…
The emerging material class of complex-oxides, where manipulation of physical properties lead to new functionalities at their heterointerfaces, is expected to open new frontiers in Spintronics. For example, SrRuO_3 is a promising material…