Related papers: Quantum magnets with weakly confined spinons: Mult…
The elementary excitations of a state of matter consisting of large collection of interacting particles can be very different from the original particles. In the most interesting examples, the particles effectively decompose into smaller…
Quantum magnetism is one of the most active areas of research in condensed matter physics. There is significant research interest specially in low-dimensional quantum spin systems. Such systems have a large number of experimental…
Conventional wisdom dictates that quantum effects become unimportant at high temperatures. In magnets, when the thermal energy exceeds interactions between atomic magnetic moments, the moments are usually uncorrelated, and classical…
S=1/2 quantum spin chains and ladders with random exchange coupling are studied by using an effective low-energy field theory and transfer matrix methods. Effects of the nonlocal correlations of exchange couplings are investigated…
The insertion of a magnetic impurity in a superconductor induces a first order quantum phase transition as the coupling to the electronic spin density increases. As the transition is crossed, a discontinuity is exhibited by various…
We consider a linear quench from the paramagnetic to ferromagnetic phase in the quantum Ising chain interacting with a static spin environment. Both decoherence from the environment and non-adiabaticity of the evolution near a critical…
Of great recent interest in condensed matter physics are phenomena of coexistence of quantum and classical properties in the same material. Such duality occurs in certain mixed-spin antiferromagnets composed of quantum spin chains…
We study quantum-fluctuation-driven fractionalized phases in the vicinity of altermagnetic order. First, the long-range magnetic orders in the vicinity of collinear altermagnetism are identified; these feature a non-coplanar "orbital…
We analyze the ground state properties of the two-dimensional quantum antiferromagnet with a S=1/2 Kondo impurity. Perturbation theory around the strong Kondo coupling limit is developed and the results compared with studies, based on exact…
In spin-based architectures of quantum devices, the hyperfine interaction between the electron spin qubit and the nuclear spin environment remains one of the main sources of decoherence. This paper provides a short review of the current…
The theory of weak quantum measurements is developed for quantum dot spin qubits. Building on recent experiments, we propose a control cycle to prepare, manipulate, weakly measure, and perform quantum state tomography. This is accomplished…
We study effects of interladder coupling on critical magnetic properties of spin ladder systems doped with small concentrations of nonmagnetic impurities, using the scaling theory together with quantum Monte Carlo (QMC) calculations.…
The interpretation of the magnetic phase diagrams of strongly correlated electron systems remains controversial. In particular, the physics of quantum phase transitions, which occur at zero temperature, is still enigmatic. Heavy-fermion…
The ground state of a quantum spin chain is a natural playground for investigating correlations. Nevertheless, not all correlations are genuinely of quantum nature. Here we review the recent progress to quantify the 'quantumness' of the…
We investigate quantum impurity problems, where a local magnetic moment is coupled to the spin density of a bosonic environment, leading to bosonic versions of the standard Kondo and Anderson impurity models. In a physical situation, these…
We review recent theoretical and experimental advances toward understanding the effects of nuclear spins in confined nanostructures. These systems, which include quantum dots, defect centers, and molecular magnets, are particularly…
Spin-state transition, also known as spin crossover, plays a key role in diverse systems, including minerals and biological materials. In theory, the boundary range between the low- and high-spin states is expected to enrich the transition…
The phenomenology of quantum phase transitions concerns physics at low temperatures and energies, and corresponding solid-state experiments often reach millikelvin temperatures. However, this is a scale where in many solids the influence of…
We study quantum Hall ferromagnets in the presence of a random electrostatic impurity potential, within the framework of a classical non-linear sigma model. We discuss the behaviour of the system using a heuristic picture for the…
The nonlinear ballistic conductance of three-dimensional quantum microconstrictions, which contain magnetic impurities, is investigated. The nonlinear part of the conductance, which is due to the interaction of electrons with magnetic…