Electron spin manipulation and readout through an optical fiber

Abstract

The electron spin of nitrogen--vacancy (NV) centers in diamond offers a solid-state quantum bit and enables high-precision magnetic-field sensing on the nanoscale. Implementation of these approaches in a fiber format would offer unique opportunities for a broad range of technologies ranging from quantum information to neuroscience and bioimaging. Here, we demonstrate an ultracompact fiber-optic probe where a diamond microcrystal with a well-defined orientation of spin quantization NV axes is attached to the fiber tip, allowing the electron spins of NV centers to be manipulated, polarized, and read out through a fiber-optic waveguide integrated with a two-wire microwave transmission line. The microwave field transmitted through this line is used to manipulate the orientation of electron spins in NV centers through the electron-spin resonance tuned by an external magnetic field. The electron spin is then optically initialized and read out, with the initializing laser radiation and the photoluminescence spin-readout return from NV centers delivered by the same optical fiber.

The Dawn of Quantum Biophotonics

“…Fig. 7.25) [50,51]. The photoluminescence spin-readout return from NV centers is captured and delivered by the same optical fiber, allowing the two-dimensional profile of the magnetic field to be imaged with high speed and high sensitivity.…”

“…(c) Image of a prototype fiber-optic magnetometer and thermometer. Adapted from [50,51] sensors, microscopic images, photolithography, optical nanostructures, quantum logic operations, etc. All these applications, however, were aimed at controlling electronic motions, molecular vibrations and rotations using shaped electromagnetic radiation in the frequency range spanning from infrared to optical to ultraviolet range.…”

Room-temperature magnetic gradiometry with fiber-coupled nitrogen-vacancy centers in diamond

“…As shown in the earlier work [7][8][9]11], in the presence of a well-calibrated bias magnetic field, the external magnetic field B can be retrieved from four pairs of spectral features in the ODMR I Ω spectra observed at magnetic resonance frequencies corresponding to the projections of the field B on the four possible directions of N-V axes in the crystal lattice of diamond [ Fig. 2…”

“…While the highest sensitivities of NV-diamond-based magnetic-field sensing and gradiometry have been achieved using confocal microscopy [10,11], optical fibers have been recently shown [11-13] to offer a missing link for a practical implementation of NVdiamond-based sensing in a variety of environments, including magnetic-field and temperature measurements in biological systems.…”

Microwave-induced thermogenetic activation of single cells

“…[21][22][23] This laser radiation couples the 3 A ground electronic state to the 3 E excited state, giving rise to photoluminescence (PL), featuring a characteristic zero-phonon line, which is observed at approximately 637 nm at room temperature against a broad phonon-sideband line, stretching down to 800 nm. Photoluminescence emitted by laser-initialized NV centers within the 630-800-nm wavelength range is collected by the same optical fiber, 18,19 and is transmitted through this fiber to the detection system, consisting of a silicon photodiode, a low-noise preamplifier, and a lock-in amplifier (Fig. 1).…”