Constructive Interference Between Disordered Couplings Enhances   Multiparty Entanglement in Quantum Heisenberg Spin Glass Models
  Disordered systems form one of the centrestages of research in many body sciences and lead to a plethora of interesting phenomena and applications. A paradigmatic disordered system consists of an one-dimensional array of quantum spin-1/2 particles, governed by the Heisenberg spin glass Hamiltonian with natural or engineered quenched disordered couplings in an external magnetic field. These systems allow disorder-induced enhancement for bipartite and multipartite observables. Here we show that simultaneous application of independent quenched disorders results in disorder-induced enhancement, while the same is absent with individual application of the same disorders. We term the phenomenon as constructive interference and the corresponding parameter stretches as the Venus regions. Interestingly, it has only been observed for multiparty entanglement and is absent for the single- and two-party physical quantities. 
Utkarsh Mishra, Debraj Rakshit, R. Prabhu, Aditi Sen De, Ujjwal Sen
quant-ph cond-mat.dis-nn cond-mat.str-el