共查询到20条相似文献,搜索用时 15 毫秒
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Temporal Ramsey fringes that are due to light scattering by coherently prepared rubidium atoms diffusing through a cell containing neon as a buffer gas have been observed. The effect leads to increasing magneto-optical rotation of cw light polarization at weak magnetic fields. 相似文献
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Hermanspahn N Haffner H Kluge H Quint W Stahl S Verdu J Werth G 《Physical review letters》2000,84(3):427-430
We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus. 相似文献
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C. Mavroyannis 《Applied physics. B, Lasers and optics》2001,73(1):39-50
We have considered the interference spectra that occur at the three-photon generated frequency arising from the interaction
of three laser fields with a four-level atom, where two of the laser fields are on two-photon resonance with the three levels
forming a “λ” scheme while the third laser operates between the second ground and the second excited state of the atom. At
low intensities of all three laser fields, the overall intensity of the peak at the three-photon generated frequency, describing
the spectrum of an electron in the second excited state, depends on the strength of the combined field of the two laser fields
that are on two-photon resonance and it takes negative values. This indicates that light amplification without population
inversion is likely to occur at the three-photon generated frequency. The combined field of the three laser fields induces
multiphoton excitations near the three-photon generated frequency, whose peaks are characterized by linewidths which are much
less than the natural linewidths of the atoms. These excitations describe absorption or stimulating emission processes depending
on the values of the detunings of the laser fields. The derived results are graphically presented and discussed.
Received: 24 January 2001 / Published online: 8 June 2001 相似文献
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Pankaj K. Jha Hebin Li Vladimir A. Sautenkov Yuri V. Rostovtsev Marlan O. Scully 《Optics Communications》2011,284(10-11):2538-2541
We present an experimental and theoretical study of phase-dependent interference effects in multi-photon excitation under bichromatic radio-frequency (rf) field. Using an intense rf pulse, we study the interference between the three-photon and one-photon transition between the Zeeman sub-levels of the ground state of 87Rb that allows us to determine the carrier-envelope phase of the fields even for long pulses. 相似文献
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Yu.L. Sokolov V.P. Yakovlev V.G. Pal'chikov Yu.A. Pchelin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):27-36
The properties of two-dimensional magnetic traps for laser-cooled atoms are analysed using complex functions. The two components
of the magnetic field from a series of parallel, infinitely long, current-carrying wires are represented by a single complex
number. The regions of the field where paramagnetic atoms can be trapped occur where the magnetic field is zero. The locations
of the zeroes of the field are obtained as the solution to a polynomial and the multiplicity m of the solution determines both the 2(m + 1)-pole nature of the trap and the field gradient through the centre. The zeroes of the field can be merged or split by
varying the locations of the currents, their strengths or by applying a uniform magnetic field. The theory is applied to magnetic
traps created from long thin wires or permanent magnets on a substrate. The properties of a number of magnetic trap configurations
used for atom guides are discussed.
Received 28 February 2001 and Received in final form 6 July 2001 相似文献
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Coherent conversion between a Raman pump field and its Stokes field is observed in a Raman process with a strong atomic spin wave initially prepared by another Raman process operated in the stimulated emission regime. The oscillatory behavior resembles the Rabi oscillation in atomic population in a two-level atomic system driven by a strong light field. The Rabi-like oscillation frequency is found to be related to the strength of the prebuilt atomic spin wave. High conversion efficiency of 40% from the Raman pump field to the Stokes field is recorded and it is independent of the input Raman pump field. This process can act as a photon frequency multiplexer and may find wide applications in quantum information science. 相似文献
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Circular polarization measurements on the =468.6 nm light emitted in the4He IIn=3-n=4 transition show that the excited states of ions emerging from anuntilted carbon foil in an external magnetic field are polarized. The polarization is parallel to the external field, increases with the strength of the field until a maximum is reached at 40 mT, and then decreases. 相似文献
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Scheme for implementing an economical phase-covariant quantum cloning machine of distant atomic qubits with single-photon interference
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By means of cavity-assisted photon interference, a simple scheme is proposed to implement a symmetric economical phase-covariant quantum cloning machine of two remote qubits, with each in a separate cavity. With our present scheme, a high-fidelity cloning machine is realized. Our scheme may be quite useful in terms of distributed quantum information processing. 相似文献
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Y. Z. Wang L. Liu X. Z. Chen X. J. Wang S. W. Fang W. Q. Cai S. Y. Zhou Y. S. Liu 《Applied physics. B, Lasers and optics》1994,58(4):327-331
This paper reports an experimental study on the collimation and decollimation of an atomic beam in a misaligned standing wave, in which the effective detuning caused by the Doppler effect is affected by the longitudinal velocity of the atomic beam. The experiment shows that in a strong field with red detuning between laser field and atomic transition frequency, laser heating in a normal standing wave becomes laser cooling in a misaligned standing wave for an approriate misalignment angle. For blue detuning, laser cooling in a standing wave can also become laser heating in a misaligned standing wave for an appropriate condition. These results ca be used in controling atomic motion. 相似文献
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The effect of vacuum-induced coherence (VIC) on the gain of lasing without inversion (LWI) is studied in an open four-level atomic system with Doppler broadening for both cases: co- and counter-propagating probe and driving fields. The results show that: (1) in general, for a fixed VIC strength, LWI gain decreases monotonously with the value of the Doppler broadening width increasing. Regardless of the Doppler broadening being obvious or not, the LWI gain much larger than that without VIC always can be gotten by choosing suitable VIC strength, i.e. values of two factors p1 and p2 which represent the VIC effect. (2) Varying p1 or p2 will produce remarkable different influence on the LWI gain, and the influence is closely related to the value of the Doppler broadening width. (3) In the case of counter-propagating probe and driving fields, when the Doppler broadening is large enough, gain oscillation occurs. For the same value of the Doppler broadening width, the oscillation amplitude increases with increasing values of strength of VIC. (4) The atomic exit and injection rates also can dramatically affect LWI gain. (5) The LWI gain for the co-propagating probe and driving fields is always larger than that for the counter-propagating probe and driving fields. (6) A much larger LWI gain in open system than that in the corresponding closed system can be obtained. 相似文献
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We present results of real-time tracking of atomic two-electron dynamics in an autoionizing transient wave packet in krypton. A coherent superposition of two Fano resonances is excited with a femtosecond extreme-ultraviolet pulse. The evolution of the corresponding wave packet is subsequently probed with a delayed infrared pulse. In our specific case, we get access to the interference between one- and two-electron excitation channels in the launched wave packet, which is superimposed on its decay through autoionization. A simple model is able to account for the observed dynamical evolution of this wave packet. 相似文献
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