Publications de Martin Mourigal

Temperature dependence of the(pi,0)anomaly in the excitation spectrum of the 2D quantum Heisenberg antiferromagnet

Martin Mourigal, Henrik Moodysson Rønnow, Goran Nilsen

It is well established that in the low-temperature limit, the two-dimensional quantum Heisenberg antiferromagnet on a square lattice (2DQHAFSL) exhibits an anomaly in its spectrum at short-wavelengths on the zone-boundary. In the vicinity of the (pi, 0) po ...

IOP PUBLISHING LTD2020

Probing multi-spinon excitations outside of the two-spinon continuum in the antiferromagnetic spin chain cuprate Sr2CuO3

Martin Mourigal, Henrik Moodysson Rønnow, Thorsten Schmitt

One-dimensional (1D) magnetic insulators have attracted significant interest as a platform for studying quasiparticle fractionalization, quantum criticality, and emergent phenomena. The spin-1/2 Heisenberg chain with antiferromagnetic nearest neighbour int ...

Nature Research2018

Fractional excitations in the square-lattice quantum antiferromagnet

Dmitri Ivanov, Bastien Dalla Piazza, Martin Mourigal, Henrik Moodysson Rønnow, Goran Nilsen, Mechthild Enderle

Quantum magnets have occupied the fertile ground between many-body theory and low-temperature experiments on real materials since the early days of quantum mechanics. However, our understanding of even deceptively simple systems of interacting spin-1/2 par ...

Nature Publishing Group2015

Fractional spinon excitations in the quantum Heisenberg antiferromagnetic chain

Martin Mourigal, Henrik Moodysson Rønnow, Mechthild Enderle, Jean-Sebastien Caux

One of the simplest quantum many-body systems is the spin-1/2 Heisenberg antiferromagnetic chain, a linear array of interacting magnetic moments. Its exact ground state is a macroscopic singlet entangling all spins in the chain. Its elementary excitations, ...

Nature Publishing Group2013

Unified one-band Hubbard model for magnetic and electronic spectra of the parent compounds of cuprate superconductors

Helmuth Berger, Marco Grioni, Bastien Dalla Piazza, Martin Mourigal, Henrik Moodysson Rønnow, Marco Guarise, Thorsten Schmitt

Using low-energy projection of the one-band t-t′-t′′ Hubbard model we derive an effective spin Hamiltonian and its spin-wave expansion to order 1/S. We fit the spin-wave dispersion of several parent compounds to the high-temperature superconducting cuprate ...

American Physical Society2012

Spin-orbital separation in the quasi-one-dimensional Mott insulator Sr2CuO3

Martin Mourigal, Henrik Moodysson Rønnow, Jean-Sebastien Caux, Thorsten Schmitt

When viewed as an elementary particle, the electron has spin and charge. When binding to the atomic nucleus, it also acquires an angular momentum quantum number corresponding to the quantized atomic orbital it occupies. Even if electrons in solids form ban ...

2012

Order and Dynamics of Model Quantum Antiferromagnets

Martin Mourigal

The spin-1/2 Heisenberg antiferromagnets in one and two dimensions are important models in quantum magnetism in which many-body effects play a crucial role. Their collective excitations are associated with quasiparticles the interaction of which are diffic ...

EPFL2011