We study the statistical mechanics and the equilibrium dynamics of a system of classical Heisenberg spins with frustrated interactions on a d -dimensional simple hypercubic lattice, in the limit of infinite dimensionality d -> infinity . In the analysis we ...
Quantum spin liquids are highly entangled magnetic states with exotic properties. The S = 1/2 square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin liquid state. Isostru ...
The dynamics of the S = 3/2 kagome antiferromagnet chromium jarosite, KCr3(OD)(6)(SO4)(2), was studied using high-resolution neutron time-of-flight spectroscopy on a polycrystalline sample with a nearly stoichiometric magnetic lattice [2.8(2)% Cr vacancies ...
The continuous reduction of the structural size in nanotechnology slowed down over the last decade, approaching the natural limit of single atoms as building blocks of matter. Therefore, intensive research is directed toward exploring new frontiers, in par ...
Under magnetic fields, quantum magnets often undergo exotic phase transitions with various kinds of order. The discovery of a sequence of fractional magnetization plateaus in the Shastry-Sutherland compound SrCu2(BO3)(2) has played a central role in the hi ...
Bound-states of particles are an interesting problem in quantum mechanics dating back to 1931 Bethe's solution of spin-1/2 Heisenberg chain. These exotic composite states are realized in quantum magnets and are detectable in inelastic neutron scattering (I ...
Quantum magnetism remains a hot topic in condensed matter physics due to its complexity and possible powerful and significant applications in data storage and memory. To understand how the materials can achieve these goals, one should have a clear idea abo ...
Co-Zn-Mn chiral cubic magnets display versatile magnetic skyrmion phases, including equilibrium phases stable far above and far below room temperature, and the facile creation of robust far-from-equilibrium skyrmion states. In this system, compositional di ...
In spin systems, geometrical frustration describes the impossibility of minimizing simultaneously all the interactions in a Hamiltonian, often giving rise to macroscopic ground-state degeneracies and emergent low-temperature physics. In this thesis, combin ...
This thesis is motivated by recent experiments on systems described by extensions of the one-dimensional transverse-field Ising (TFI) model where (1) finite-size properties of Ising-ordered phases -- specifically, ground state level crossings -- were obser ...
We present a first-principles investigation of the structural, electronic, and magnetic properties of the pristine and Fe-doped alpha-MnO2 using density-functional theory with extended Hubbard functionals. The onsite U and intersite V Hubbard parameters ar ...
We studied the magnetic excitations in the quasi-one-dimensional (q-1D) ladder subsystem of Sr14-xCaxCu24O41 (SCCO) using Cu L-3-edge resonant inelastic X-ray scattering (RIXS). By comparing momentum-resolved RIXS spectra with high (x = 12.2) and without ( ...
We examine the ground-state phase diagram and thermal phase transitions in a plaquettized fully frustrated bilayer spin-1/2 Heisenberg model. Based on a combined analysis from sign-problem free quantum Monte Carlo simulations, perturbation theory, and free ...
Motivated by the recent success of tensor networks to calculate the residual entropy of spin ice and kagome Ising models, we develop a general framework to study frustrated Ising models in terms of infinite tensor networks that can be contracted using stan ...
Despite their simple formulation, short-range classical antiferromagnetic Ising models on frustrated lattices give rise to exotic phases of matter, in particular, due to their macroscopic ground-state degeneracy. Recent experiments on artificial spin syste ...
The spin-1/2 Heisenberg model on the pyrochlore lattice is an iconic frustrated three-dimensional spin system with a rich phase diagram. Besides hosting several ordered phases, the model is debated to possess a spin-liquid ground state when only nearest-ne ...
The study of magnetic frustration has been interesting due to the variety of magnetic ordering observed at low temperatures. At these temperatures thermal fluctuations become redundant and quantum fluctuations play a significant role in the determining the ...
This thesis is devoted to the investigation of static and dynamic properties of
two different sets of quantum magnets with neutron scattering techniques and
the help of linear spin wave theory.
Both systems are copper-based with spin-1/2, which makes them ...
This thesis presents results of studies of novel compounds modeling complex fundamental physics phenomena. Cu2OSO4 is a copper based magnetic Mott Insulator system, where spin half magnetic moments form a new type of lattice. These intrinsically quantum pi ...
Potassium chromium jarosite, KCr3(OH)(6)(SO4)(2) (Cr-jarosite), is considered a promising candidate to display spin liquid behavior due to the strong magnetic frustration imposed by the crystal structure. However, the ground state magnetic properties have ...
