Here, we report on the observation of a random to chaotic temperature transformation in the statistics of nearest-neighbor spacings of Fano-Feshbach resonances in the ultracold polarized gas of ...thulium-169 atoms. We associate this transformation to the appearance of so-called d resonances as well as the shift of other resonances with the temperature. In addition to this statistical change, it has been observed that the characters of s- and d-resonance temperature shifts are quite different: s resonances experience almost no shift or even negative shift with the temperature, while d resonances experience an obvious positive shift. The sign change was attributed to the difference in polarizability of Feshbach molecules and free thulium atoms. In addition, careful analysis of the broad Fano-Feshbach resonances enabled the determination of the sign of thulium's background scattering length. A rethermalization experiment made it possible to estimate a length value of a_{bg}=+144±38 a.u. This indicates that thulium atoms are suitable for achieving Bose-Einstein condensation.
Control over the interaction between single photons and individual optical emitters is an outstanding problem in quantum science and engineering. It is of interest for ultimate control over light ...quanta, as well as for potential applications such as efficient photon collection, single-photon switching and transistors, and long-range optical coupling of quantum bits. Recently, substantial advances have been made towards these goals, based on modifying photon fields around an emitter using high-finesse optical cavities. Here we demonstrate a cavity-free, broadband approach for engineering photon-emitter interactions via subwavelength confinement of optical fields near metallic nanostructures. When a single CdSe quantum dot is optically excited in close proximity to a silver nanowire, emission from the quantum dot couples directly to guided surface plasmons in the nanowire, causing the wire's ends to light up. Non-classical photon correlations between the emission from the quantum dot and the ends of the nanowire demonstrate that the latter stems from the generation of single, quantized plasmons. Results from a large number of devices show that efficient coupling is accompanied by more than 2.5-fold enhancement of the quantum dot spontaneous emission, in good agreement with theoretical predictions.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Hybrid quantum devices, in which dissimilar quantum systems are combined in order to attain qualities not available with either system alone, may enable far-reaching control in quantum measurement, ...sensing, and information processing. A paradigmatic example is trapped ultracold atoms, which offer excellent quantum coherent properties, coupled to nanoscale solid-state systems, which allow for strong interactions. We demonstrate a deterministic interface between a single trapped rubidium atom and a nanoscale photonic crystal cavity. Precise control over the atom's position allows us to probe the cavity near-field with a resolution below the diffraction limit and to observe large atom-photon coupling. This approach may enable the realization of integrated, strongly coupled quantum nano-optical circuits.
Plasmonics allows light to be localized on length scales much shorter than its wavelength, which makes it possible to integrate photonics and electronics on the nanoscale. Magneto-optical materials ...are appealing for applications in plasmonics because they open up the possibility of using external magnetic fields in plasmonic devices. Here, we fabricate a new magneto-optical material, a magnetoplasmonic crystal, that consists of a nanostructured noble-metal film on top of a ferromagnetic dielectric, and we demonstrate an enhanced Kerr effect with this material. Such magnetoplasmonic crystals could have applications in telecommunications, magnetic field sensing and all-optical magnetic data storage.
A new copper(
ii
) complex (
I
) was obtained by the reaction of a sterically crowded 2,4-di-(
tert
-butyl)-9-chloro-benzo5,61,4oxazine2,3-
b
phenoxazine bridging ligand with Cu(
ii
) ...hexafluoroacetylacetonate. Compound
I
is a quasi-one-dimensional complex in which the Cu(hfac)
2
moieties are co-crystallized with the triphenodioxazine molecules through only weak Cu N short intermolecular interactions (the Cu N distances are 2.732 and 2.752 Å). The magnetic AC susceptibility data show that in spite of the absence of zero-field splitting in the Cu(
ii
) ion with
S
= 1/2, the compound demonstrates a slow magnetic relaxation behaviour at a weak applied magnetic field (
H
DC
= 500 Oe). The EPR spectra and DC magnetic measurements show the strong axial anisotropy of the g-tensor. The temperature dependence of the relaxation time is well described by the combination of one-phonon direct and two-phonon Raman processes.
A new copper(
ii
) complex (
I
) was obtained by the reaction of a sterically crowded 2,4-di-(
tert
-butyl)-9-chloro-benzo5,61,4oxazine2,3-
b
phenoxazine bridging ligand with Cu(
ii
) hexafluoroacetylacetonate.
Synthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH
2
)Co(TDA)
2
2H
2
O (
I
), (pipH
2
2+
= piperazine dication, TDA
2−
= thiodiacetic anion) ...are described. X-ray diffraction studies reveal the first coordination sphere of the Co(
ii
) ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur-oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency-domain Fourier-transform (FD-FT) THz-EPR spectroscopy, and high-level
ab initio
SA-CASSCF/NEVPT2 quantum chemical calculations reveal a strong "easy-plane" type magnetic anisotropy (
D
+54 cm
−1
) of complex
I
. The complex shows field-induced slow relaxation of magnetization at an applied DC field of 1000 Oe.
Novel (pipH
2
)Co(TDA)
2
is a rare example of a quasi-octahedral Co(
ii
) complex with mixed sulfur-oxygen environment exhibiting strong "easy-plane" type magnetic anisotropy and demonstrating field-induced single-ion magnet (SIM) behavior.
The RED-100 experiment Akimov, D.Yu; Alexandrov, I.S.; Alyev, R.R. ...
Journal of instrumentation,
11/2022, Letnik:
17, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Abstract
The RED-100 two-phase xenon emission detector has been
deployed at 19-m distance from the reactor core of the Kalinin
Nuclear Power Plant (KNPP) in 2021–2022 for investigation of the
...possibility to observe reactor antineutrinos using the effect of
coherent elastic neutrino-nucleus scattering (CE
ν
NS). The
performance of the main systems of the RED-100 setup at operating
nuclear power plant is described. There is no correlation of the
radioactive background at the experimental setup site with ON and
OFF states of the reactor. The data taking run was carried out at
the beginning of the year 2022 and covered both the reactor OFF and
ON periods.
Abstract
The RED-100 experiment with a liquid xenon target was
carried out at Kalinin Nuclear Power Plant. The goal of the
experiment is the detection and study of the coherent elastic
neutrino ...nucleus scattering process (CEνNS) for the low-energy
antineutrinos in close vicinity to a reactor core. A good
understanding of the external radioactive background is needed to
achieve this goal. This paper describes the external background
conditions for the RED-100 experiment at Kalinin Nuclear Power
Plant.
Strong coupling between two quanta of different excitations leads to the formation of a hybridized state that paves a way for exploiting new degrees of freedom to control phenomena with high ...efficiency and precision. A magnon polaron is the hybridized state of a phonon and a magnon, the elementary quanta of lattice vibrations and spin waves in a magnetically ordered material. A magnon polaron can be formed at the intersection of the magnon and phonon dispersions, where their frequencies coincide. The observation of magnon polarons in the time domain has remained extremely challenging because the weak interaction of magnons and phonons and their short lifetimes jeopardize the strong coupling required for the formation of a hybridized state. Here, we overcome these limitations by spatial matching of magnons and phonons in a metallic ferromagnet with a nanoscale periodic surface pattern. The spatial overlap of the selected phonon and magnon modes formed in the periodic ferromagnetic structure results in a high coupling strength which, in combination with their long lifetimes, allows us to find clear evidence of an optically excited magnon polaron. We show that the symmetries of the localized magnon and phonon states play a crucial role in the magnon polaron formation and its manifestation in the optically excited magnetic transients.
We show that the magnetization of a thin ferromagnetic (Ga,Mn)As layer can be modulated by picosecond acoustic pulses. In this approach a picosecond strain pulse injected into the structure induces a ...tilt of the magnetization vector M, followed by the precession of M around its equilibrium orientation. This effect can be understood in terms of changes in magnetocrystalline anisotropy induced by the pulse. A model where only one anisotropy constant is affected by the strain pulse provides a good description of the observed time-dependent response.
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