8 papers
Witnessing entanglement in quantum magnets using neutron scattering
A. Scheie, Pontus Laurell, A. M. Samarakoon +6
We demonstrate how quantum entanglement can be directly witnessed in the quasi-1D Heisenberg antiferromagnet KCuF. We apply three entanglement witnesses --- one-tangle, two-tan…
Exact resummation of the Holstein-Primakoff expansion and differential equation approach to operator square-roots
Michael Vogl, Pontus Laurell, Hao Zhang +2
Operator square-roots are ubiquitous in theoretical physics. They appear, for example, in the Holstein-Primakoff representation of spin operators and in the Klein-Gordon equation.…
Momentum-space entanglement after a quench in one-dimensional disordered fermionic systems
Rex Lundgren, Fangli Liu, Pontus Laurell +1
We numerically investigate the momentum-space entanglement entropy and entanglement spectrum of the random-dimer model and its generalizations, which circumvent Anderson localizati…
Dynamical and thermal magnetic properties of the Kitaev spin liquid candidate -RuCl
Pontus Laurell, Satoshi Okamoto
What is the correct low-energy spin Hamiltonian description of -RuCl? The material is a promising Kitaev spin liquid candidate, but is also known to order magnetically, the…
Deriving models for the Kitaev spin-liquid candidate material -RuCl from first principles
Casey Eichstaedt, Yi Zhang, Pontus Laurell +3
We use the constrained random phase approximation (cRPA) to derive from first principles the Ru- Wannier function based model for the Kitaev spin-liquid candidate material…
Analogue of Hamilton-Jacobi theory for the time-evolution operator
Michael Vogl, Pontus Laurell, Aaron D. Barr +1
In this paper we develop an analogue of Hamilton-Jacobi theory for the time-evolution operator of a quantum many-particle system. The theory offers a useful approach to develop app…