Magnetic measurements on micrometer-sized samples under high pressure using designed NV centers

Abstract

Pressure is a unique tool to tune the interplay between structural, electronic and magnetic interactions. It leads to remarkable properties of materials such as recent temperature records in superconductivity. Advanced magnetic measurements under very high pressure in the Diamond Anvil Cell (DAC) use synchrotron approaches but these are lacking a formal link to the macroscopic magnetic properties. We report an alternative method consisting in optical magnetometry based on nitrogen-vacancy (NV) centers created at the surface of a diamond anvil. We illustrate the method by two measurements realized at room and low temperature respectively: the pressure evolution of the magnetization of an iron bead up to 30 GPa showing the iron ferromagnetic collapse and the detection of the superconducting transition of MgB 2 at 7 GPa. * These authors contributed equally to this work. 1 arXiv:1812.09894v1 [cond-mat.mes-hall]

Magnetism of Body‐Centered Cubic Fe‐Ni Alloys Under Pressure: Strain‐Enhanced Ferromagnetism at the Phase Transitions

“…Magnetic fields are applied parallel to the long axis of the sample in the saturation magnetization experiments (SIRM), where the sample becomes fully saturated by 0.1–0.3 T, with the remanence being measured in the same direction. This explains why the SIRM technique (Wei & Gilder, 2013; Wei et al., 2017), and others based on magnetic remanence (Gilder & Glen, 1998; Hsieh et al., 2018; Lesik et al., 2019), serve as sensitive probes of the magnetic state of material under pressure and consistently find the persistence of ferromagnetism into the hcp stability field.…”

Principles and techniques of the quantum diamond microscope

“…Fortunately a QDM is relatively straightforward to build, and the technology is sufficiently mature that running a QDM experiment from start to finish is straightforward. As diamond characteristics and NV sensing techniques improve, a growing range of QDM capabilities and applications can be expected, including in extreme environments, e.g., high pressure, high temperature, and cryogenic [120,137,138]. QDM imaging of magnetic fields is well established with a rapidly expanding application space.…”

Diamond with nitrogen: states, control, and applications

“…Among the famous N n V m complex family in over 500 electronic optical centers, NV − center is most intensively studied and applied, owing to its outstanding properties such as strong fluorescence, long-lived ground state electron spin coherence, optical spin polarization or readout, state-selective intersystem crossing probabilities, etc [10,54,136]. It is thus could be used to detect the electric field of a single electron at a distance of ~25 nm within 1 s of averaging, absorb and re-emit single photon for quantum computing and information processing, provide robust quantum memories, and sense magnetic field, stress, temperature or current, etc [10,[136][137][138][139][140][141][142][143].…”

“…This could lead to completely integrated, on-chip, atomic sensors [139]. An imaging strain sensor under high pressure and magnetic field based on NV center was realized (refer to Figure 11) [140,141].…”