Related papers: Order by quenched disorder in the model triangular…
Frustrated magnets can have accidental ground state degeneracies which may be lifted by various forms of disorder, for example in the form of thermal or quantum fluctuations. This order by disorder (ObD) paradigm is well established in…
We study the effect of quenched disorder on the ordering of orbital and magnetic degrees of freedom in a two-dimensional, two-band double-exchange model for $e_g$ electrons coupled to Jahn-Teller distortions. Using a real-space Monte Carlo…
We investigate the structural and magnetic phase transitions in EuTi1-xNbxO3 with synchrotron powder X-ray diffraction (XRD), resonant ultrasound spectroscopy (RUS), and magnetization measurements. Upon Nb-doping, the Pm-3m to I4/mcm…
Several doped 6H hexagonal ruthenates, having the general formula Ba3MRu2O9, have been studied over a significant period of time in order to understand the unusual magnetism of ruthenium metal. However, among them, the M=Fe compound appears…
We use neutron scattering to study the structural distortion and antiferromagnetic (AFM) order in LaFeAsO$_{1-x}$F$_{x}$ as the system is doped with fluorine (F) to induce superconductivity. In the undoped state, LaFeAsO exhibits a…
Measurements of the specific heat on the system Ca$_{1-x}$La$_{x}$MnO$_{3}$ (% $x\leq 0.10$) are reported. Particular attention is paid to the effect that doping the parent compound with electrons by substitution of La for Ca has on the…
Partial disorder --the microscopic coexistence of long-range magnetic order and disorder-- is a rare phenomenon, that has been experimental and theoretically reported in some Ising- or easy plane-spin systems, driven by entropic effects at…
A detailed study of the structural and magnetic properties of a spin-$5/2$ triangular lattice antiferromagnet RbFe(HPO$_{3}$)$_{2}$ is presented using x-ray diffraction, magnetization, heat capacity, and $^{31}$P nuclear magnetic resonance…
The double-tetrahedral chain in a longitudinal magnetic field, whose nodal lattice sites occupied by the localized Ising spins regularly alternate with triangular plaquettes with the dynamics described by the Hubbard model, is rigorously…
Structural and magnetic properties of a two-dimensional spin-$\frac{5}{2}$ frustrated triangular lattice antiferromagnet NH$_{4}$Fe(PO$_{3}$F)$_2$ are explored via x-ray diffraction, magnetic susceptibility, high-field magnetization, heat…
We examine the orbital and magnetic order of the two orbital Hubbard model within dynamical mean field theory. The model describes the low energy physics of a partially filled $e_g$-band as can be found in some transition metal compounds.…
Geometric frustration among competing spin exchanges can give rise to novel quantum phases by enhancing fluctuations that drive magnetic systems beyond the classical regime. We investigate the frustrated array of strongly correlated spin…
Ground state of the periodic Anderson model on a triangular lattice is systematically investigated by the mean-field approximation. We found that the model exhibits two different types of partially disordered states: one is at half filling…
Geometrically frustrated magnetism has attracted tremendous attention while chemical doping has been utilized as an important tool to probe frustrated magnetism in various systems. Here we perform a systematic study by doping non-magnetic…
We study effects of quenched bond disorder in frustrated easy-plane antiferromagnets in two space dimensions, using a combination of analytical and numerical techniques. We consider local-moment systems which display non-collinear…
The two dimensional Hubbard model in the presence of diagonal and off-diagonal disorder is studied at half filling with a finite temperature quantum Monte Carlo method. Magnetic correlations as well as the electronic compressibility are…
From first principles calculations we find that the nearest and next nearest neighbor superexchange interactions between Fe ions in LaOFeAs are large, antiferromagnetic (AF), and give rise to a frustrated magnetic ground state which…
We theoretically study the magnetic phase diagram of a three-dimensional topological Kondo insulator by means of real-space dynamical mean field theory. We find that ferromagnetically ordered states become stable upon hole doping. Besides a…
Based on experimental observations in A{x}MO{2} (A = Na, Li; M = Co, Ni), a model for suppression of magnetic frustration by electron doping in a nearest-neighbour antiferromagnetic triangular lattice is presented. It is found that…
The interplay of disorder and spin-fluctuation effects in a disordered antiferromagnet is studied. In the weak-disorder regime (W \le U), while the energy gap decreases rapidly with disorder, the sublattice magnetization, including quantum…