SearcharxivSearch

arXiv · 2312.08026

Red-shift effect on the zero field splitting for negatively charged nitrogen-vacancy centers in diamond

Abstract

The zero field splitting (ZFS) quantifies the energy difference for the ground electron spin-triplet of a nitrogen-vacancy center in the absence of external fields. The values of the ZFS play a key role in determining the Larmor precession of the Bloch sphere and the Rabi oscillation of a spin system. The ZFS is generally detected using coherent spin manipulation by sweeping microwaves (MWs) at frequencies close to resonance with the ZFS. In this letter, we report our experimental observations of the red-shift effect on the ZFS as a function of the MW power for two different thermal environments of a sample. We find an asymptotic property of the red shifts of the ZFS. Given the identical initial thermal equilibrium states of the sample, the differences in the raw values of the ZFS between the two cases randomly vary from 47 kHz to 1505 kHz over the entire experimental range. According to the asymptotic approximation, the differences are reduced to 29-166 kHz with a standard deviation of 49 kHz, suggesting a significant elimination of the red-shift effect. To the best of our knowledge, no other study has addressed the quantification and elimination of the red shift-effect of the MW field dependence using the asymptotic approximation.

Explore related subjects

Keep this discovery

BibTeXRIS

Wang Zheng, Zhang Jintao, Feng Xiaojuan, Xing Li. 2023-12-13. Red-shift effect on the zero field splitting for negatively charged nitrogen-vacancy centers in diamond. https://arxiv.org/abs/2312.08026

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Janus Dipoles: Fundamentals, Realizations, and Emerging Applications

The Janus dipole - featuring orthogonally oriented electric and magnetic dipoles with a 90-degree phase difference - has emerged as a powerful paradigm for wave manipulation. Unlike traditional Huygens dipoles used for directional control, this unique configuration exhibits strongly asymmetric, face-selective near-field behavior while maintaining a quasi-isotropic far-field radiation pattern. These remarkable properties make the Janus dipole an essential platform for directional wave shaping, with wide-ranging applications in on-chip photonics, quantum interactions, and wireless power transfer. This review systematically traces the rapid development of the Janus dipole from its foundational theoretical inception to its diverse implementation platforms across optical, microwave, and acoustic frequencies. In this paper, we explore the governing principles, classify realization strategies into passive Janus dipoles, active Janus dipoles, and advanced near-field coupling control, and highlight emerging frontiers. By bridging foundational electrodynamics with advanced device engineering, this paper serves as an essential reference and roadmap for researchers designing next-generation, highly integrated, and compact wave-manipulation systems.

physics.app-ph

Scattering-robust Imaging of Azimuthal Features with Enhanced Resolution

Imaging through scattering media remains a long-standing challenge in numerous real-world applications, ranging from medical imaging to long-distance sensing. Recently, illumination consisting of a single orbital angular momentum (OAM) mode, which is structured in the azimuthal coordinate, has been shown to provide enhanced resolution for imaging objects with azimuthal features, with the resolution becoming maximum at an optimal OAM value. However, in the presence of scattering, single-mode fields, which are spatially fully coherent, cause the imaging resolution to decrease significantly due to speckle formation. In this work, we employ azimuthally partially coherent fields and experimentally demonstrate imaging of azimuthal features with enhanced resolution in the presence of scattering. We show that lower degree of azimuthal coherence in such illumination leads to increased robustness against scattering while the azimuthal structure of the illumination ensures enhanced resolution. We derive the condition for best imaging resolution, and we report increase of imaging contrast in scattering from about 7% to 50% as the illumination is changed from a single-mode fully coherent field to that of an azimuthal partially coherent field.

physics.app-ph

Influence of magnetic fields on the performance of spin-orbit torque magnetic random-access memory

Spin-orbit torque magnetic random-access memory (SOT-MRAM) offers high speed, ultrahigh endurance, and compatibility with advanced semiconductor processes, making it a promising candidate for next-generation nonvolatile memory. However, intrinsic bias fields in magnetic tunnel junctions (MTJs), originating from reference-layer stray fields and interlayer coupling, cause asymmetric critical switching currents and increased energy consumption. Existing compensation approaches usually introduce additional magnetic layers into the MTJ stack, which increases fabrication complexity and limits wafer-scale integration. Here, we propose a bias-compensation strategy without modifying the MTJ stack by engineering local stray magnetic fields through magnetic filling materials in vertical interconnect access (VIA) channels during the back-end-of-line process. Micromagnetic simulations show that the proposed magnetic filling layer can provide the required auxiliary field for deterministic switching and significantly suppress write-current asymmetry. By optimizing the MTJ position relative to the magnetic filling structure, the write-current bias ratio is reduced from 21.6% in the conventional design to 1.3%. The approach is also applicable to in-plane magnetic anisotropy SOT-MTJs, reducing the bias ratio from 19.8% to -0.2%. Scaling analysis further demonstrates that the compensation effect remains effective when the device size is reduced to 20% of the original dimension (MTJ diameter approximately 10 nm), indicating its potential for high-density SOT-MRAM integration.

physics.app-ph