Group Seminar at LMU: Quantum Sensing Using NV Centers in Diamond

Tim Höhn
LMU München, Schellingstr. 4
Seminar room H 107
Tuesday 01/14, 09:15am

Abstract:The nitrogen-vacancy (NV) center in diamond is a promising nanoscale quantum sensor for temperature, strain, electric and magnetic fields. Its applicability as a tool to investigate novel materials of interest has sparked widespread attention. Employing this suite of sensing techniques in a high-pressure environment represents an important challenge at the interface of fields ranging from geophysics to condensed matter. To this end, a new sensing platform is introduced, based upon directly integrating NV centers into the culet of diamond anvil cells (DAC) – one of the workhorses of high-pressure science. In this talk, I will demonstrate the capability of this platform by presenting results of diffraction-limited imaging of stress fields, quantifying all six (normal and shear) stress tensor components, as well as vector magnetic fields in iron and gadolinium up to pressures of 60 GPa and for temperatures ranging from 25 to 340 K. Furthermore, this hybrid sensor is utilized to elucidate the stress-induced demagnetization of the Martian mineral pyrrhotite with unprecedented accuracy. In addition to DC vector magnetometry, I will highlight a complementary NV-sensing modality using T1 noise spectroscopy, enabling us to characterize phase transitions even in the absence of static magnetic signatures. Eventually, I will report on measurements of the ferroelectric material bismuth ferrite and proposals to investigate the layer-dependent magnetization of thin-film chromium triiodide.