Related papers: Quantum Superposition and Entanglement in Spin-Gla…
Atom-field entanglement is shown to play a crucial role for the onset of spatial self-organization of ultracold atoms in an optical lattice within a high-Q cavity. Like particles on a seesaw, the atoms feel a different potential depending…
Coherence arises from the superposition principle, where it plays a central role in quantum mechanics. In [Phys.Rev.Lett.114,210401(2015)], it has been shown that the freezing phenomenon of quantum correlations beyond entanglement, is…
Recently entanglement suppression was proposed to be one potential origin of emergent symmetries. In this work, we extend this theoretical framework to accommodate particles with arbitrary spins and/or arbitrary group representations. As…
Measures are introduced to quantify the degree of superposition in mixed states with respect to orthogonal decompositions of the Hilbert space of a quantum system. These superposition measures can be regarded as analogues to entanglement…
A geometrically frustrated (GF) magnet consists of localised magnetic moments, spins, whose orientation cannot be arranged to simultaneously minimise their interaction energies. Such materials may host novel fascinating phases of matter,…
We investigate the entanglement spectrum near criticality in finite quantum spin chains. Using finite size scaling we show that when approaching a quantum phase transition, the Schmidt gap, i.e., the difference between the two largest…
The spin-statistics theorem is generalized to include quantum entanglement. Specifically, within the context of spin entanglement, we prove that isotropic spin-correlated (ISC) states must occur in pairs. This pairing process can be…
We study weakly coupled antiferromagnetic spin chains in their ordered phase by combinining an exact solution of the single-chain problem with an RPA analysis of the interchain interaction. A single chain is described by a quantum…
We review our earlier studies on the order parameter distribution of the quantum Sherrington-Kirkpatrick (SK) model. Through Monte Carlo technique, we investigate the behavior of the order parameter distribution at finite temperatures. The…
This paper is divided into two parts. The first part concerns several standard scenarios for how short-range spin glasses might behave at low temperature. Earlier theorems of the authors are reviewed, and some new results presented,…
A spin glass is a diluted magnetic material in which the magnetic moments are randomly interacting, with a huge number of metastable states which prevent reaching equilibrium. Spin-glass models are conceptually simple, but require very…
We examine the idea, postulated by Phillips et al., that a finite resistivity in $T \to 0$ limit in disordered granular superconducting (SC) films is explained as a consequence of the absence of phase stiffness in a phase glass (PG)…
We analyze the conditional quantum state of a mechanical mirror in an optomechanical system subject to continuous measurement, feedback control, and quantum filtering. We identify a parameter regime in which the mirror exhibits momentum…
We discuss the effects of magnetic impurities on d-wave superconductors. We calculate the electron mediated RKKY interaction between the impurity spins in a d-wave superconductor and find that it decays as $r^{-3}$ at large distances. We…
We analyze the steady state regime of systems interpolating between spin glasses and ferromagnets under a tapping dynamics recently introduced by analogy with the dynamics of mechanically perturbed granular media. A crossover from a second…
Entanglement is a cornerstone in quantum information science, yet detecting it efficiently remains a challenging task. Focusing on non-positive partially transposed (NPT) states, we establish a hierarchy among entropy-based, majorization,…
Phenomena such as state-swap, quadrature squeezing, entanglement and violation of entanglement inequalities are frequently reported to occur in quantum systems only. It is shown here that these effects can also occur in cholesteric liquid…
The phase diagram of spins 1/2 embedded in a magnetic field mutually interacting antiferromagnetically is determined. Contrary to the ferromagnetic case where a second order quantum phase transition occurs, a first order transition is…
In amorphous superconductors, superconducting and vortex pinning properties are strongly linked to the absence of long range order. Consequently, superconductivity and vortex phases can be studied to probe the underlying microstructure and…
Spontaneous breaking of translational symmetry---known as `density wave' order---is common in nature. However such states are strongly sensitive to impurities or other forms of frozen disorder leading to fascinating glassy phenomena. We…