Publications de Simone Borroni

Energy domain versus time domain precursor fluctuations above the Verwey transition in magnetite

Henrik Moodysson Rønnow, Fabrizio Carbone, Simone Borroni, Gregory Scott Tucker

We study the dynamics and interactions of the critical fluctuations of the Verwey transition in magnetite (Fe3O4) in the pretransition region by means of inelastic neutron scattering experiments on a natural single crystal. We find that a Delta(5) mode int ...

AMER PHYSICAL SOC2020

Light scattering from the critical modes of the Verwey transition in magnetite

Fabrizio Carbone, Simone Borroni

We present inelastic light scattering data on a single crystal of magnetite (Fe3O4) across the Verwey transition. We identify anomalies of the lattice vibrations that originate from strong coupling to electronic excitations. We reveal spectroscopic signatu ...

AMER PHYSICAL SOC2018

New Insights into the Verwey Transition in Magnetite

Simone Borroni

Magnetite (Fe

_3

O

_4

) is the first magnetic material discovered by mankind. Despite thousands of years of applications, from the magnetic compass to data storage, and decades of basic research, it remains among the most fascinating materials for physicis ...

EPFL2018

Coherent generation of symmetry-forbidden phonons by light-induced electron-phonon interactions in magnetite

Frank van Mourik, Oleg Yazyev, Christopher Alexander Arrell, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni

Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. In second-order or weakly first-order tr ...

Amer Physical Soc2017

Mapping the lattice dynamical anomaly of the order parameters across the Verwey transition in magnetite

Henrik Moodysson Rønnow, Fabrizio Carbone, Andrea Pisoni, Francesco Pennacchio, Simone Borroni, Gregory Scott Tucker

We present inelastic neutron scattering data across the Verwey transition in magnetite, obtained for a single crystal via a detwinning method. We provide direct evidence of the influence of the charge order on the transverse-acoustic phonons, associated wi ...

2017

Real-Time Observation of Phonon-Mediated σ−π Interband Scattering in MgB2

Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni, Ting Tan

In systems having an anisotropic electronic structure, such as the layered materials graphite, graphene, and cuprates, impulsive light excitation can coherently stimulate specific bosonic modes, with exotic consequences for the emergent electronic properti ...

2017

A versatile setup for ultrafast broadband optical spectroscopy of coherent collective modes in strongly correlated quantum systems

Frank van Mourik, Christopher Alexander Arrell, Fabrizio Carbone, Andreas Helmut Christian Mann, Edoardo Baldini, Simone Borroni

A femtosecond pump-probe setup is described that is optimised for broadband tran- sient reflectivity experiments on solid samples over a wide temperature range. By combining high temporal resolution and a broad detection window, this apparatus can investig ...

2016