Agenda

Next Quantum Material Seminar:

Thursday, February 23rd 2023 at 2:00 pm

Gediminas Simutis  (PSI Villigen, Switzerland)

“ Uniaxial control of quantum matter”

To access this seminar:

Institut Néel CNRS, Building K, Room Rémy Lemaire  (K223)

Abstract: Quantum matter is characterised by competing and intertwined orders. Here I will present our recent advances in using uniaxial pressure as a clean “surgical” tool to tune quantum phases while simultaneously obtaining microscopic insights via scattering experiments. In particular, we address two directions – minimizing the background and enabling the tuning in-situ.
First, we study spin order in cuprate superconductors characterized by small moments, which remains challenging for pressure studies. We overcome this challenge by designing a low-background uniaxial strain cell, optimizing the experiment based on neutron-tracing simulations and using aggressive focusing and energy analysis enabled by the ThALES spectrometer at ILL [1]. We show that the spin order parameter in cuprates is uniaxial and coupled to the charge channel [2].
Second, to further improve the feasibility and speed of such experiments, we have designed a new in-situ uniaxial device for large-scale facility research based on an actuator-motor mechanism, efficient feedback loops and the sample-holder design enabling rapid exchange of the samples [3]. I will demonstrate the improved capabilities of this device reporting the control of charge order in cuprates [4] and tuning of magnetic phases in skyrmion materials.
    
[1] Boehm et al., Neutron News 26, 18 (2015)
[2] Simutis et al., Nature Communications Physics 5, 296 (2022)
[3] Simutis et al., in publication at Review of Scientific Instruments and arXiv:2207.13194 (2023)
[4] Guguchia et al., in preparation

The organizers:

Elsa Lhotel (elsa.lhotel@neel.cnrs.fr)
Florence Levy-Bertrand (florence.levy-bertrand@neel.cnrs.fr)