Magnetic shielding of quantum entanglement states

Abstract

The measure of quantum entanglement is determined for any dimer, either ferromagnetic or antiferromagnetic, spin-1/2 Heisenberg systems in the presence of external magnetic field. The physical quantity proposed as a measure of thermal quantum entanglement is the distance between states defined through the Hilbert-Schmidt norm. It has been shown that for ferromagnetic systems there is no entanglement at all. However, although under applied magnetic field, antiferromagnetic spin-1/2 dimers exhibit entanglement for temperatures below the decoherence temperature -the one above which the entanglement vanishes. In addition to that, the decoherence temperature shows to be proportional to the exchange coupling constant and independent on the applied magnetic field, consequently, the entanglement may not be destroyed by external magnetic fields -the phenomenon of magnetic shielding effect of quantum entanglement states. This effect is discussed for the binuclear nitrosyl iron complex [Fe2(SC3H5N2)2(NO)4] and it is foreseen that the quantum entanglement survives even under high magnetic fields of Tesla orders of magnitude.

Phase Diagram and Quantum Entanglement Properties of a Pentamer S = 1/2 Heisenberg Spin Cluster

“…The interest in quantum entanglement brings the localized spin systems of cluster geometry to the attention of the theoreticians [21][22][23][24]. In such context, a variety of geometries can be mentioned, like dimers [25][26][27][28][29][30][31][32][33][34][35][36], trimers [37][38][39][40][41][42][43] or four-site structures [44][45][46][47][48][49][50][51][52]. Attention is paid to design of cluster structures offering advantageous properties due to interplay between geometry and spin-spin interactions [53,54].…”

Magnetic Field Effect on Dynamics of Entanglement for Time-dependent Harmonic Oscillator

“…vacuum [4,3], thermal [5], squeezed [11], coherent • • • ) have been considered as prototypical continuum variables, which is natural because they can be created and assisted via linear optics. Recently, it was shown that the entanglement can be assisted via temperature [5], magnetic field [17] and both in [18], but most of them dealt with time independent potential.…”