共查询到20条相似文献,搜索用时 0 毫秒
1.
A. D. Sargsyan R. K. Mirzoyan A. S. Sarkisyan A. H. Amiryan D. H. Sarkisyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2014,49(1):20-27
We study narrow-band N-type resonance formed in a Λ-system of 85Rb atoms. Even when thin (micrometer) optical cells are employed, N-type resonance has a high contrast. We used radiation of two cw diode lasers. Peculiarities of splitting of N-type resonance into six components in a strong transverse magnetic field are studied experimentally and theoretically and the conversion to the Paschen-Back regime on the hyperfine structure of 85Rb atoms is recorded. 相似文献
2.
Electromagnetically induced transparency in a Zeeman-sublevels Λ-system of cold ~(87)Rb atoms in free space
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We report the experimental investigation of electromagnetically induced transparency(EIT) in a Zeeman-sublevelsΛ-type system of cold ~(87)Rb atoms in free space. We use the Zeeman substates of the hyperfine energy states 5~2S_(1/2), F = 2 and 5~2P_(3/2), F = 2 of ~(87)Rb D_2 line to form a Λ-type EIT scheme. The EIT signal is obtained by scanning the probe light over 1 MHz in 4 ms with an 80 MHz arbitrary waveform generator. More than 97% transparency and 100 k Hz EIT window are observed. This EIT scheme is suited for an application of pulsed coherent storage atom clock(Yan B, et al. 2009 Phys.Rev. A 79 063820). 相似文献
3.
O. M. Parshkov 《Optics and Spectroscopy》2017,123(3):430-439
The effect of separation of linearly polarized short probe pulses of electromagnetically induced transparency in the field of linearly polarized coupling radiation is modeled numerically. It is shown that the input-probe pulses polarized parallel or perpendicular to the input-probe field propagate in the medium without changing the state of their polarization. If the input-probe radiation is weak compared to the coupling radiation, then the probe field inside the medium is the sum of two independently propagating linearly polarized normal modes, which are excited by the projections of the input-probe pulse onto the direction of polarization of the coupling radiation and onto the perpendicular direction, respectively. The normal modes have the same phase velocities, but different velocities of their real envelopes. This circumstance leads to the rotation of the plane of polarization of the total probe field at short distances and to its separation into two pulses with mutually perpendicular directions of polarization at long distances. At a high intensity of the probe radiation, the input-probe pulse decays into pulses the planes of polarization of which are not mutually perpendicular. Under these conditions, it is impossible to represent the probe radiation as a sum of normal modes. The modeling is performed in the scheme of degenerate quantum transitions between states of levels 3 P 0, 3 P 1 0, and 3 P 2 of isotope 208Pb taking into account the Doppler broadening of spectral lines. 相似文献
4.
Nonclassical properties in the resonant interaction of a three level Λ-type atom with two-mode field in coherent state 总被引:1,自引:0,他引:1
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In this paper, we study the nonclassical properties of the
electromagnetic field resulting from the interaction of a
three-level Λ-type atom with a two-mode field initially
in the coherent state, such as squeezing properties and
sub-Poisson statistics. We show that the squeezing can be
enhanced by selective atomic measurement. 相似文献
5.
X. Q. Jiang Y. L. Wang X. D. Sun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(3):427-430
We study the spontaneous emission spectrum of a three-level Λ-type
atom in a damped cavity using the resolvent operator. The shape of the
spectrum is strongly influenced by the detuning and the coupling intensity
between the atom and the cavity mode. Especially, we find that the
splittings of the upper level of the three-level Λ-type atom are
different in strong coupling regime, intermediate coupling regime and weak
coupling regimes. 相似文献
6.
Gregory S. Adkins 《Physics letters. A》2018,382(23):1545-1549
The nonrelativistic hydrogen atom in dimensions is the reference system for perturbative schemes used in dimensionally regularized nonrelativistic effective field theories to describe hydrogen-like atoms. Solutions to the D-dimensional Schrödinger–Coulomb equation are given in the form of a double power series. Energies and normalization integrals are obtained numerically and also perturbatively in terms of ?. The utility of the series expansion is demonstrated by the calculation of the divergent expectation value . 相似文献
7.
The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type three-level atom has been established. And the formal solution of the Schrodinger equation in the representation and its average number are obtained. Then, the photon squeezing effects are studied through numerical calculation. The results show that the q deformation nonlinear action has a lot of influence on the quantum coherence and quantum properties. When q approaches 1, the theory reduces to the common linear theory. 相似文献
8.
The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type threelevel atom has been established. And the formal solution of the Schrodinger equation in the representation and its average number are obtained. Then, the photon squeezing effects are studied through numerical calculation. The results show that the q deformation nonlinear action has a lot of influence on the quantum coherence and quantum properties. When q approaches 1, the theory reduces to the common linear theory. 相似文献
9.
10.
Dong-Liang Chen Ye-Hong Chen Yang Liu Zhi-Cheng Shi Jie Song Yan Xia 《Frontiers of Physics》2022,17(5):52501
We propose a protocol for detecting a single atom in a cavity with the help of the χ(2) nonlinear medium. When the χ(2) nonlinear medium is driven by an external laser field, the cavity mode will be squeezed, and thus one can obtain an exponentially enhanced light-matter coupling. Such a strong coupling between the atom and the cavity field can significantly change the output photon flux, the quantum fluctuations, the quantum statistical property, and the photon number distributions of the cavity field. This provides practical strategies to determine the presence or absence of an atom in a cavity. The proposed protocol exhibits some advantages, such as controllable squeezing strength and exponential increase of atom-cavity coupling strength, which make the experimental phenomenon more obvious. We hope that this protocol can supplement the existing intracavity single-atom detection protocols and provide a promise for quantum sensing in different quantum systems. 相似文献
11.
Ultracold neutral atoms in higher bands of an optical lattice provide a natural avenue to emulate orbital physics in solid state materials. Here, we report the realization of 87Rb Bose–Einstein condensates in the fourth and seventh Bloch bands of a hexagonal boron-nitride optical lattice, exhibiting remarkably long coherence time through active cooling. Using band mapping spectroscopy, we observe that atoms condensed at the energy minimum of L point(K1 and K2 points) in the... 相似文献
12.
A. I. Dmitriev A. D. Talantsev S. V. Zaitsev Yu. A. Danilov M. V. Dorokhin B. N. Zvonkov O. V. Koplak R. B. Morgunov 《Journal of Experimental and Theoretical Physics》2011,113(1):138-147
Ferromagnetic ordering of two types (depending on the sample geometry) is found to occur in a thin Ga1 − x
Mn
x
As alloy layer (Mn δ layer) in heterostructures containing an InGaAs/GaAs quantum well. Singular samples in which the δ Mn
layer is parallel to the (001) GaAs plane exhibit the “3/2” Bloch temperature dependence of magnetization, and vicinal samples
in which the δ Mn layer deviates from the (001) GaAs plane exhibit a “percolation” ferromagnetic transition. The photoluminescence
polarization of the quantum well is shown to follow changes in the magnetization of the Mn δ layer as a function of temperature
according to the Bloch law in the singular samples and to a percolation law in the vicinal samples. 相似文献
13.
We have studied the influence of a constant magnetic field on the possibility of the formation of dark states and on the behavior of the alignment of an ensemble of atoms with the filled ns shell the (n + 1)3 S 1 state of which is excited by the Λ-scheme from states n 3 P 1 and n 3 P 2, which, in turn, are populated by means of an axially symmetric interaction. 相似文献
14.
We observe strong energy-dependent quantum defects in the scaled-energy Stark spectra for |M| = 1 Rydberg states of barium atoms at three scaled energies: ε = 2.000,ε = 2.500 and ε = 3.000.In an attempt to explain the observations,theoretical calculations of closed orbit theory based on a model potential including core effect are performed for non-hydrogenic atoms.While such a potential has been uniformly successful for alkali atoms with a single valence electron,it fails to match experimental results for barium atoms in the 6snp Rydberg states with two valence electrons.Our study points out that this discrepancy is due to the strong perturbation from the 5d8p state,which voids the simple approximation for constant quantum defects of principle quantum number n. 相似文献
15.
16.
I–V characterization of an n-type quantum well infrared photodetector which consists of stepped and graded barriers has been done under dark at temperatures between 20–300 K. Different current transport mechanisms and transition between them have been observed at temperature around 47 K. Activation energies of the electrons at various bias voltages have been obtained from the temperature dependent I–V measurements. Activation energy at zero bias has been calculated by extrapolating the bias dependence of the activation energies. Ground state energies and barrier heights of the four different quantum wells have been calculated by using an iterative technique, which depends on experimentally obtained activation energy. Ground state energies also have been calculated with transfer matrix technique and compared with iteration results. Incorporating the effect of high electron density induced electron exchange interaction on ground state energies; more consistent results with theoretical transfer matrix calculations have been obtained. 相似文献
17.
The last decade of research on κ-Minkowski noncommutative spacetime has been strongly characterized by a controversy concerning the speed of propagation of massless particles. Most arguments suggested that this speed should depend on the momentum of the particle strongly enough to be of interest for some ongoing experimental studies. But the only explicit derivations of worldlines in κ-Minkowski predicted no momentum dependence for the speed of massless particles. We return to this controversy equipped with the recent understanding that in some quantum spacetimes coincidences of events assessed by an observer who is distant from the events can be artifactual. We therefore set up our investigation in such a way that we never rely on the assessment of coincidences of events by distant observers. This allows us to verify explicitly that in κ-Minkowski simultaneously-emitted massless particles of different momentum are detected at different times, and establish a linear dependence of the detection times on momentum. 相似文献
18.
On the binding energies of excitons in polar quantum well structures in a weak electric field
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The binding energies of excitons in quantum well structures subjected to an applied uniform electric field by taking into account the exciton longitudinal optical phonon interaction is calculated. The binding energies and corresponding Stark shifts for Ⅲ-Ⅴ and Ⅱ-Ⅵ compound semiconductor quantum well structures have been numerically computed. The results for GaAs/A1GaAs and ZnCdSe/ZnSe quantum wells are given and discussed. Theoretical results show that the exciton-phonon coupling reduces both the exciton binding energies and the Stark shifts by screening the Coulomb interaction. This effect is observable experimentally and cannot be neglected. 相似文献
19.
Ao LinKaori Kobayashi Hua-Gen YuGregory E. Hall James T. MuckermanTrevor J. Sears Anthony J. Merer 《Journal of Molecular Spectroscopy》2002,214(2):216-224
The rotationally resolved Ã(010)-X?(000) spectrum of DCCl between 12 880 and 12 964 cm−1 was measured using frequency-modulated laser absorption spectroscopy of jet-cooled and ambient temperature samples. Transitions to levels with Ka′=0 and 1 were assigned, and their analysis leads to improved accuracy of both the ground state rotational constants of DCCl and, when combined with existing data for HCCl, the geometry of the radical. In addition to the expected perpendicular band structure, a number of parallel (Δ Ka=0) subbands were observed. Their intensity derives from a combination of c-type Coriolis coupling and axis-switching (J. T. Hougen and J. K. G. Watson, 1965, Can. J. Phys.43, 298) resulting from the change in geometry between the two states. The two contributions have been calculated for the (010)-(000) band of DCCl and previously recorded data for HCCl. Satisfactory agreement with experimental measurements was obtained. The Coriolis contributions are small for these transitions, but may add to or subtract from the axis-switching. For higher bending excitation in the upper state, Coriolis coupling is predicted to make larger contributions to the parallel subband intensities. 相似文献
20.
We study the lattice QCD ΛcN phase shifts for the 3S1-3D1 coupled channel using both the leading order covariant chiral effective theory and the next-to-leading order non-relativistic chiral effective field theory(ChEFT).We show that although it is possible to describe simultaneously the 3S1 and 3D1 phase shifts and the inelasticity η1,the fitted energy range is quite small,only up to E<... 相似文献