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1.
We study phenomenon of electromagnetically induced absorption (EIA) in the Hanle configuration by applying a perturbative
method to solve linear system of optical Bloch equations (OBEs) for the case of closed F
g
= 1 → F
e
= 2 transition. The method is applied assuming stationary case and a weak laser fields (Ω ≪ Γ, i.e., Rabi frequency small
compared to spontaneous emission rate). This way, we calculate (both numerically and analytically) higher order corrections
to density matrix. Odd corrections give contributions to optical coherences, while even corrections contribute to populations
and Zeeman coherences. The method gives insight into mechanism of transfer of coherences and transfer of populations between
Zeeman sublevels. We have found that the ground-state coherences (2nd correction to coherences) are crucial for the 4th correction
to the change of populations which brings EIA type behavior of the Hanle spectrum. Using exact analytical expressions we further
discuss further the role of decoherence of the ground-state sublevels when forming EIA. 相似文献
2.
Optical pumping and population transfer of nuclear-spin states of caesium atoms in high magnetic fields
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Nuclear-spin states of gaseous-state Cs atoms in the ground state
are optically manipulated using a Ti:sapphire laser in a magnetic
field of 1.516T, in which optical coupling of the nuclear-spin
states is achieved through hyperfine interactions between electrons
and nuclei. The steady-state population distribution in the
hyperfine Zeeman sublevels of the ground state is detected by using
a tunable diode laser. Furthermore, the state population transfer
among the hyperfine Zeeman sublevels, which results from the
collision-induced modification \delta a(\bm S \cdot \bm I) of the
hyperfine interaction of Cs in the ground state due to stochastic
collisions between Cs atoms and buffer-gas molecules, is studied at
different buffer-gas pressures. The experimental results show that
high-field optical pumping and the small change \delta a(\bm S
\cdot \bm I) of the hyperfine interaction can strongly cause the
state population transfer and spin-state interchange among the
hyperfine Zeeman sublevels. The calculated results maybe explain the
steady-state population in hyperfine Zeeman sublevels in terms of
rates of optical-pumping, electron-spin flip, nuclear spin flip, and
electron-nuclear spin flip-flop transitions among the hyperfine
Zeeman sublevels of the ground state of Cs atoms. This method may be
applied to the nuclear-spin-based solid-state quantum computation. 相似文献
3.
4.
强磁场中的Cs原子有较大的超精细塞曼分裂,实验用频率可调谐的窄线宽半导体激光调谐到各超精细塞曼能级上进行光泵浦,利用稳态吸收谱方法研究了原子的光泵浦。表明基态超精细相互作用的碰撞修正项导致的驰豫跃迁是谱形状和电子自旋极化新特征的根缘。同时提出了强场下极化度的一种测量方法。 相似文献
5.
6.
A theory is presented for the intensities of hyperfine components in saturation spectroscopy. We use a diagrammatic approach to nonlinear processes to derive closed-form formulas for the intensities of recoil doublets and of Doppler-generated level crossings. We discuss the influence of the terms introduced by hyperfine coherences in saturation spectroscopy. We also demonstrate spectroscopic stability when the hyperfine splittings are negligible. A catalog of simple formulas is given in view of applications to current spectroscopy and is illustrated by recent examples, including Doppler-free polarization spectroscopy. The extension to other sub-Doppler techniques such as two-photon Doppler-free spectroscopy is outlined. 相似文献
7.
利用原子的塞曼光谱对半导体激光器进行稳频 总被引:4,自引:1,他引:3
中性原子的超精细能级在磁场中产生塞曼分裂 ,另外 ,左旋和右旋圆偏振光激发下原子的跃迁选择定则不同 ,因此 ,原子在超精细塞曼能级间的吸收谱峰相对无磁场条件下的吸收谱峰有一定的移动。利用这一点 ,验证了一种简单、灵活的方法对半导体激光器进行稳频 ,使激光器的线宽稳到小于 1MHz。通过对实验结果的分析 ,发现由左旋和右旋圆偏振光激发引起的原子吸收谱峰移动之和与饱和吸收峰半高宽相等时 ,稳频效果最好 相似文献
8.
9.
Gammon D Efros AL Kennedy TA Rosen M Katzer DS Park D Brown SW Korenev VL Merkulov IA 《Physical review letters》2001,86(22):5176-5179
Fine and hyperfine splittings arising from electron, hole, and nuclear spin interactions in the magneto-optical spectra of individual localized excitons are studied. We explain the magnetic field dependence of the energy splitting through competition between Zeeman, exchange, and hyperfine interactions. An unexpectedly small hyperfine contribution to the splitting close to zero applied field is described well by the interplay between fluctuations of the hyperfine field experienced by the nuclear spin and nuclear dipole/dipole interactions. 相似文献
10.
D. Nettels R. Müller-Siebert S. Ulzega A. Weis 《Applied physics. B, Lasers and optics》2003,77(6-7):563-570
We report magnetic resonance experiments with optical detection performed on cesium atoms trapped in a crystalline Hematrix. Multi-photon transitions, i.e., processes in which several radio-frequency photons are absorbed simultaneously in a given hyperfine Zeeman multiplet of the ground state, were the central topic of these studies. The long relaxation times of spin coherences of Cs in solid He allow such transitions to be spectrally resolved in fields as low as 1 mT. We observed all allowed multi-photon transitions up to the M=8 transition in the F=4 state. We compare the experimental spectra with theoretical spectra obtained from numerical solutions of the Liouville equation that include optical pumping and the interaction with the static and oscillating fields. Multi-photon transitions may find applications in magnetometry, suppress systematic effects in EDM experiments, and allow the study of relaxation phenomena in doped He crystals. The demonstration of these features is still hindered by inhomogeneous line broadening. PACS 76.70.Hb; 32.80.Wr; 32.30.Dx; 32.60.+i 相似文献
11.
G. Stanzel 《Physics letters. A》1974,47(4):283-284
The line-crossing effect between Zeeman components of different isotopes was studied experimentally and theoretically in forward-scattered light in order to determine the isotope shift and hyperfine structure. The influence of the spectral distribution of the incident radiation was properly considered. 相似文献
12.
本论述了Rb^87基态超精细塞曼能级光泵磁共振的偏振激发特性,给出了塞曼能级跃迁谱线随抽运光偏振特性的变化。 相似文献
13.
All-optical formation of molecules with spin degree of freedom in an atomic Bose-Einstein condensate
We have performed a two-photon photoassociation experiment in an atomic Bose-Einstein condensate of 87Rb with the spin degree of freedom, which is created by an all-optical method with CO2 lasers. The spinor character of the created molecules has been revealed by the photoassociation spectrum with a new structure. The hyperfine structure of the created molecules near the dissociation limit is identified by observations of the Zeeman and AC-Stark effects of the molecules. We have also demonstrated the spin-selective creation of molecules. This result would open the new possibility of research on novel molecular spinor BEC. 相似文献
14.
Cviklinski J Ortalo J Laurat J Bramati A Pinard M Giacobino E 《Physical review letters》2008,101(13):133601
Using electromagnetically induced transparency in a cesium vapor, we demonstrate experimentally that the quantum state of a light beam can be mapped into the long-lived Zeeman coherences of an atomic ground state. Two noncommuting variables carried by light are simultaneously stored and subsequently read out, with no noise added. We compare the case where a tunable single sideband is stored independently of the other one to the case where the two symmetrical sidebands are stored using the same electromagnetically induced transparency window. 相似文献
15.
Takayuki Yamazaki Akira Miyazaki Taikan Suehara Toshio Namba Shoji Asai Tomio Kobayashi Haruo Saito Yuichi Urushizaki Isamu Ogawa Toshitaka Idehara Svilen Sabchevski 《Hyperfine Interactions》2012,212(1-3):141-147
Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS, about 203 GHz) is an important observable but all previous measurements of Ps-HFS had been measured indirectly using Zeeman splitting. There might be the unknown systematic errors on the uniformity of magnetic field. We are trying to measure Ps-HFS directly using sub-THz radiation. We developed an optical system to accumulate high power (about 10 kW) radiation in a Fabry-Pérot resonant cavity and observed the positronium hyperfine transition for the first time. 相似文献
16.
H. Ring R.T. Carter J.R. Huber 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,4(1):73-81
We demonstrate the application of a pulsed magnetic field for the creation and manipulation of coherences in molecular systems,
using quantum beat spectroscopy for the detection of the dynamics of the molecular superposition states. In all cases, the
experiments are performed on energy levels in electronically excited states of the (jet-cooled) CS2 molecule populated by a short laser pulse. In the basic experiment, following excitation of initially degenerate Zeeman sublevels
under zero field conditions with suitable laser polarization, quantum beats are generated at the moment the magnetic field
is switched on, even when the field is delayed by several excited state lifetimes. By quenching of the field, it is shown
that the molecule may be “frozen” in any superposition state of the participating sublevels. Using a combination of static
and pulsed fields with different orientations, the molecule can be prepared in a more general state, described by coherences
among all Zeeman substrates. This is achieved by choosing an appropriate time delay for the switched field, without any change
to the geometrical parameters of the experiment such as laser polarization or detection direction. Numerical simulations of
these dynamical coherence phenomena have been performed to support assignment and interpretation of the experimental results.
Received: 8 April 1998 / Accepted: 3 June 1998 相似文献
17.
S. Weber T. Berthold E. Ohmes M. C. Thurnauer J. R. Norris G. Kothe 《Applied magnetic resonance》1996,11(3-4):461-469
Transient electron paramagnetic resonance is used to study the secondary radical pair in plant photosystem I. Nuclear coherences are observed in the transverse magnetization at lower temperatures following light excitation. Comparative studies of deuterated and deuterated15N-substituted cyanobacteriaS. lividus indicate assignment of these coherences to nitrogen nuclei in the primary donor and deuterons in the secondary acceptor. The modulation amplitude of a deuteron matrix line, as a function of the microwave power, reveals a distinct resonance behavior. The maximum amplitude is obtained when the Rabi frequency equals the nuclear Zeeman frequency. 相似文献
18.
Bradbury FR Tyryshkin AM Sabouret G Bokor J Schenkel T Lyon SA 《Physical review letters》2006,97(17):176404
We report Stark shift measurements for 121Sb donor electron spins in silicon using pulsed electron spin resonance. Interdigitated metal gates on a Sb-implanted 28Si epilayer are used to apply the electric fields. Two quadratic Stark effects are resolved: a decrease of the hyperfine coupling between electron and nuclear spins of the donor and a decrease in electron Zeeman g factor. The hyperfine term prevails at magnetic fields of 0.35 T, while the g factor term is expected to dominate at higher magnetic fields. We discuss the results in the context of the Kane model quantum computer. 相似文献
19.
D. V. Glamazda 《Physics of Particles and Nuclei Letters》2009,6(4):325-333
A new relativistic method of one-component wave functions applicable for describing fields with arbitrary spins is suggested. This method is used to solve the problem of energy states of hydrogen-like atoms with different required accuracies and under differing conditions (rough estimate, relativistic correction, fine structure, Zeeman effect in a magnetic field, or hyperfine splitting with account of nucleus spin) 相似文献
20.
A. Buzdin 《Physica B: Condensed Matter》2012,407(11):1912-1914
We provide a general review of the properties of the non-uniform superconducting Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) phase. Special emphasis is made on the orbital and crystal structure effects which may result in the quantum transitions between the higher Landau level states and should be responsible for the strong modification of the anisotropy of the critical field. The FFLO-type instability may be also expected in ultracold Fermi gases. In these systems it is caused not by the Zeeman interaction but by the tuning of the population imbalance between two lowest hyperfine states of the atoms. We also briefly discuss their properties. 相似文献