Control of entanglement transitions in quantum spin clusters

Abstract

Quantum spin clusters provide a platform for the experimental study of many-body entanglement. Here we address a simple model of a single-molecule nanomagnet featuring N interacting spins in a transverse field. The field can control an entanglement transition (ET). We calculate the magnetization, low-energy gap, and neutron-scattering cross section and find that the ET has distinct signatures, detectable at temperatures as high as 5% of the interaction strength. The signatures are stronger for smaller clusters.

Discrete and generalized phase space techniques in critical quantum spin chains

“…and is understood as an entanglement transition which is characterized by an energy level degeneracy [8,9,19,46].…”

Principal component analysis of diffuse magnetic neutron scattering: a theoretical study

“…An illustration of the geometry of the model can be found in [Ref. 27,Fig. 1]. We take all three components of the interaction to be anti-ferromagnetic, corresponding to J < 0, and assume without loss of generality 0 ≤ γ ≤ 1 and ∆ > 0 1 .…”

“…The behaviour of the model defined by Eq. (1) has been studied extensively [27][28][29][30][31][32].…”

“…At the ET the ground state factorises exactly. These changes in the system's ground state have clear signatures in simulated low-temperature, high-resolution diffuse magnetic neutron scattering cross-sections [27]. The main question we tackle here is whether a PCA can detect these features using a more limited number of lower-resolution images.…”

Low-Temperature Magnetocaloric Properties of V12 Polyoxovanadate Molecular Magnet: A Theoretical Study

“…Magnetic tetramers composed of spins in all possible geometries—linear chain, rectangular planar structure, or tetrahedron—have attracted so far noticeable efforts of theorists. In this context, the studies focused on magnetic susceptibility [ 15 ], neutron scattering properties [ 15 , 16 ] correlations [ 17 ], and quantum entanglement [ 16 , 18 , 19 , 20 ] can be mentioned. In addition to these calculations, a material-oriented, Density Functional Theory (DFT) calculations aimed at prediction of energy levels of V12 were performed [ 14 ].…”