Neutron spectroscopy of single and entangled antiferromagnetic rings

Venue: Room A206 - Polo Ferrari 1
At: 14.30

• Dr. Tatiana Guidi  - ISIS Facility, Rutherford Appleton Laboratory (UK)

Abstract:
Molecular nanomagnets are model systems to study the spin dynamics and magnetic correlations in low dimensional magnets. Molecular wheels are a subclass of molecular magnets constituted by a finite number of magnetic ions at the vertices of regular polygons and interacting antiferromagnetically (AF). The advances in the chemical engineering of these molecules have allowed the synthesis of tailor-made systems displaying  several interesting  phenomena ranging from finite size effects on the magnetic properties of linear AF chains to the entanglement between complex spin systems. Neutron scattering techniques have been intensively and successfully used to study the microscopic properties of molecular magnets and have enabled to reveal the signatures of their quantum behaviour.
I will show how inelastic neutron scattering experiments on single crystals of molecular rings can be used to directly determine the Fourier components of the two-spin dynamical correlations [1] and to portray entanglement in weakly coupled molecular qubits [2]. Furthermore, polarized neutron diffraction experiments have been used to determine the local magnetization in finite antiferromagnetic chains and to reveal the finite size effects in their spin density distribution [3].

[1] M. Baker, T. Guidi, et al,  Nature Physics 8,  906 (2012).
[2] E Garlatti, T Guidi, et al,  Nature Commun 8, 14543  (2017).
[3] T. Guidi, et al, Nature Commun 6, 7061 (2015)..

CV:
Tatiana Guidi received her PhD in Material Science in 2004. During her Post Doc at the Universita’ Politecnica delle Marche, she spent one year as visiting Scientist at the NIST Center for Neutron Research in USA. She then joined the Magnetism and Superconductivity of quantum systems group at the Helmholtz-Zentrum Berlin in 2006. In 2008 she became permanent research staff at the ISIS Neutron and Muon source at the Rutherford Appleton Laboratory (UK)  where she is currently responsible of  the MARI neutron spectrometer. Her research activity is focused on molecular magnetism and low dimensional magnetism. She is an expert in neutron techniques and in the use of Large Scale Facilities instrumentations applied to the study of the magnetic structure and spin dynamics of molecular magnets, low dimensional magnets, superconductors, quantum magnets.