Search results for "Quantum physic"
showing 10 items of 1596 documents
Roadmap on quantum nanotechnologies
2021
Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a …
Eddy-Current Imaging with Nitrogen-Vacancy Centers in Diamond
2018
We demonstrate microwave-free eddy-current imaging using nitrogen-vacancy centers in diamond. By detecting the eddy-current induced magnetic field of conductive samples, we can distinguish between different materials and shapes and identify structural defects. Our technique allows for the discrimination of different materials according to their conductivity. The sensitivity of the measurements is calculated as 8$\times 10 ^{5}$\,S/m\,$\sqrt[]{\textrm{Hz}}$ at 3.5\,MHz, for a cylindrical sample with radius $r_0$\,=\,1\,mm and height $h$\,=\,0.1\,mm (volume $\sim$\,0.3\,mm$^3$), at a distance of 0.5\,mm. In comparison with existing technologies, the diamond-based device exhibits a superior ba…
Optically Enhanced Electric Field Sensing Using Nitrogen-Vacancy Ensembles
2021
Nitrogen-vacancy (NV) centers in diamond have shown promise as inherently localized electric-field sensors, capable of detecting individual charges with nanometer resolution. Working with NV ensembles, we demonstrate that a detailed understanding of the internal electric field environment enables enhanced sensitivity in the detection of external electric fields. We follow this logic along two complementary paths. First, using excitation tuned near the NV's zero-phonon line, we perform optically detected magnetic resonance (ODMR) spectroscopy at cryogenic temperatures in order to precisely measure the NV center's excited-state susceptibility to electric fields. In doing so, we demonstrate th…
Spiking dynamics of frequency up-converted field generated in continuous-wave excited rubidium vapours
2020
We report on spiking dynamics of frequency up-converted emission at 420 nm generated on the 6P3/2-5S1/2 transition in Rb vapour two-photon excited to the 5D5/2 level with laser light at 780 and 776 nm. The spike duration is less than the natural lifetime of any excited level involved in the interaction with both continuous and pulsed pump radiation. The spikes at 420 nm are attributed to temporal properties of the directional emission at 5.23 {\mu}m generated on the population inverted 5D5/2-6P3/2 transition. A link between the spiking regime and cooperative effects is discussed. We suggest that the observed stochastic behaviour is due to the quantum-mechanical nature of the cooperative eff…
Intensity-correlated spiking of infrared and ultraviolet emission from sodium vapors
2021
The directional spiking infrared and ultraviolet emission from sodium vapors excited to the 4D5/2 level by a continuous-wave resonant laser pump, that constitute a novel feature of the cooperative effects, has been analyzed. Cascade mirrorless lasing at 2207 and 2338 nm on population-inverted transitions and ultraviolet radiation at 330 nm that is generated due to four-wave mixing process demonstrate a high degree of intensity correlation.
Zero-field magnetometry based on nitrogen-vacancy ensembles in diamond
2018
Ensembles of nitrogen-vacancy (NV) centers in diamonds are widely utilized for magnetometry, magnetic-field imaging and magnetic-resonance detection. They have not been used for magnetometry at zero ambient field because Zeeman sublevels lose first-order sensitivity to magnetic fields as they are mixed due to crystal strain or electric fields. In this work, we realize a zero-field (ZF) magnetometer using polarization-selective microwave excitation in a 12C-enriched HPHT crystal sample. We employ circularly polarized microwaves to address specific transitions in the optically detected magnetic resonance and perform magnetometry with a noise floor of 250 pT/Hz^(1/2). This technique opens the …
Noncovalent force spectroscopy using wide-field optical and diamond-based magnetic imaging
2019
A realization of the force-induced remnant magnetization spectroscopy (FIRMS) technique of specific biomolecular binding is presented where detection is accomplished with wide-field optical and diamond-based magnetometry using an ensemble of nitrogen-vacancy (NV) color centers. The technique may be adapted for massively parallel screening of arrays of nanoscale samples.
High-Spatial-Resolution Monitoring of Strong Magnetic Field using Rb vapor Nanometric-Thin Cell
2011
We have implemented the so-called $\lambda$-Zeeman technique (LZT) to investigate individual hyperfine transitions between Zeeman sublevels of the Rb atoms in a strong external magnetic field $B$ in the range of $2500 - 5000$ G (recently it was established that LZT is very convenient for the range of $10 - 2500$ G). Atoms are confined in a nanometric thin cell (NTC) with the thickness $L = \lambda$, where $\lambda$ is the resonant wavelength 794 nm for Rb $D_1$ line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field with the frequency positions and transition probabilities depending on th…
Electromagnetically Induced Transparency and optical pumping processes formed in Cs sub-micron thin cell
2012
Abstract The Electromagnetically Induced Transparency (EIT) effect in a Λ -system formed by Cs atoms (6 S 1/2 − 6 P 3/2 − 6 S 1/2 ) confined in an extremely thin cell (ETC) (atomic column thickness L varies in the range of 800 nm –3 µm is studied both experimentally and theoretically. It is demonstrated that when the coupling laser frequency is in exact resonance with the corresponding atomic transition, the EIT resonance parameters weakly depend on L , which allows us to detect the effect at L = λ = 852 nm. EIT process reveals a striking peculiarity in case of the coupling laser detuned by Δ from the atomic transition, namely the width of the EIT resonance rapidly increases upon an in…
Dark-Line Atomic Resonances in Micrometric Rb-Vapor Layer
2007
We present measurements of dark-line resonances excited in Rb atomic vapor confined in micrometric cells (MC). In our work, the Lambda-systems on D2 line of 85Rb have been studied with the use of bi-chromatic radiation of two separate narrowband diode lasers.