BEGIN:VCALENDAR VERSION:2.0 PRODID:-//linuxsoftware.nz//NONSGML Joyous v1.4//EN BEGIN:VEVENT SUMMARY:Photoinduced dynamics of electronic\, structural and magnetic orde r in quantum materials DTSTART:20220119T160000Z DTEND:20220119T180000Z DTSTAMP:20260906T082818Z UID:fd6aef6b-c621-47a1-a450-f737821cd938 SEQUENCE:5 CREATED:20220104T124005Z DESCRIPTION:Abstract:Quantum materials exhibit a variety of different phas es that arise from the competition between different degrees of freedom – electronic\, stru­­ctural\, spin and orbital. Ultrafast techniques e nable a selective investigation of the dynamical response of these differe nt subsystems through a careful choice of pump and probe characteristics.I will present results of studies in different quantum materials using ultr afast pulses in the optical\, THz and x-ray frequency ranges.TbMnO3 is a p rototypical multiferroic\, where ferroelectric polarization arises from a cycloidal magnetic order below 27 K. The prospect of electric field contro l of magnetization dynamics makes multiferroic systems extremely appealing \, in particular in the context of ultrafast magnetic switching. Using ult rafast x-ray pulses we have investigated the magnetic order and structural dynamics in TbMnO_3 following optical and THz excitation\, shedding light onto the demagnetization pathways in this system.Mott insulators are arch etypal examples of quantum materials\, which have generated strong interes t due in part to the insulator-to-metal transition that some exhibit when the balance between on-site Coulomb repulsion and hopping is overturned. S ome Mott insulators exhibit an abrupt drop in resistivity under the applic ation of electric fields with durations of a few tens of microseconds\, wi th typical threshold fields on the order of 1-10 kV/cm. Quasi-dc electric fields well in excess of 1 – 10 kV/cm can currently be generated with ul trashort pulses in the low frequency or THz range\, which enables the inve stigation of the sub-picosecond dynamics of the electric field driven Mott transition. I will present our results on THz driven dynamics in GaTa_4Se _8\, a Mott insulator which exhibits clear electrical Mott transitions.Sho rt Bio:Elsa Abreu is a Senior Research Assistant in the Physics Department of ETH Zürich. In 2018 she was awarded a four-year Ambizione Grant from the Swiss National Science Foundation for her project on "\;Exploring superconductivity pathways in low-dimensional spin-ladder and spin-chain c ompounds"\;\, and has since then been leading a team as a part of the Ultrafast Dynamics Group.She obtained her BSc in Physics from the Institut o Superior Técnico and her MSc at Instituto Superior Técnico and Uppsala University\, Sweden. In 2014 she graduated with her PhD in Physics from B oston University\, MA\, USA\, and then moved to Switzerland to work as a p ostdoctoral fellow at ETH Zürich. LAST-MODIFIED:20220119T113100Z LOCATION:Online (Password: 353881) URL:http://df.vps.tecnico.ulisboa.pt/pt/eventos/photoinduced-dynamics-of-e lectronic-structural-and-magnetic-order-in-quantum-materials/ X-ALT-DESC;FMTTYPE=text/html:

Abstract:
Quantum materials exhibit a variety of dif ferent phases that arise from the competition between different degrees of freedom – electronic\, stru­­ctural\, spin and orbital. Ultrafast tec hniques enable a selective investigation of the dynamical response of thes e different subsystems through a careful choice of pump and probe characte ristics.

I will present results of studies in different quantum materials using ultrafast pulses in the optic al\, THz and x-ray frequency ranges.

TbMnO3 is a prototypical multiferroic\, where ferroelectric polarization arises from a cycloidal magnetic order below 27 K. The prospect of electr ic field control of magnetization dynamics makes multiferroic systems extr emely appealing\, in particular in the context of ultrafast magnetic switc hing. Using ultrafast x-ray pulses we have investigated the magnetic order and structural dynamics in TbMnO_3 following optical and THz excitation\, shedding light onto the demagnetization pathways in this system.

Mott insulators are archetypal examples of quantum materials\, which have generated strong interest due in part to th e insulator-to-metal transition that some exhibit when the balance between on-site Coulomb repulsion and hopping is overturned. Some Mott insulators exhibit an abrupt drop in resistivity under the application of electric f ields with durations of a few tens of microseconds\, with typical threshol d fields on the order of 1-10 kV/cm. Quasi-dc electric fields well in exce ss of 1 – 10 kV/cm can currently be generated with ultrashort pulses in the low frequency or THz range\, which enables the investigation of the su b-picosecond dynamics of the electric field driven Mott transition. I will present our results on THz driven dynamics in GaTa_4Se_8\, a Mott insulat or which exhibits clear electrical Mott transitions.

Short Bio:
Elsa Abreu is a Senior Research As sistant in the Physics Department of ETH Zürich. In 2018 she was awarded a four-year Ambizione Grant from the Swiss National Science Foundation for her project on "\;Exploring superconductivity pathways in low-dimensi onal spin-ladder and spin-chain compounds"\;\, and has since then been leading a team as a part of the Ultrafast Dynamics Group.

She obtained her BSc in Physics from the Instituto Superior Técnico and her MSc at Instituto Superior Técnico and Uppsala University\, Sweden. In 2014 she graduated with her PhD in Physics from Bo ston University\, MA\, USA\, and then moved to Switzerland to work as a po stdoctoral fellow at ETH Zürich.

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