共查询到20条相似文献,搜索用时 11 毫秒
1.
A. Za¨ır O. Tcherbakoff E. Mével E. Constant R. Lopez-Martens J. Mauritsson P. Johnsson A. L’Huillier 《Applied physics. B, Lasers and optics》2004,78(7-8):869-872
We investigate the temporal confinement of high order harmonic pulses generated by a femtosecond (fs) infrared (IR) pulse with a time varying polarization. We use a set of two birefringent quartz plates to modulate the IR polarization. It produces a short temporal gate of linear polarization where harmonics are efficiently generated during a small fraction of the IR pulse. By rotating one of the plates, the gate width can be continuously varied between 70 fs down to 7 fs. The XUV pulse duration is measured by cross-correlation with a probe IR pulse of 12 fs. When the gate width is decreased, a clear temporal confinement of the XUV emission is observed through the cross correlation signal. This experiment is the first direct experimental evidence in the temporal domain that the polarization gating technique can be used to significantly shorten the harmonic pulse duration. PACS 32.80.Wr; 42.65.Ky; 42.65.Re 相似文献
2.
Ranitovic P Tong XM Hogle CW Zhou X Liu Y Toshima N Murnane MM Kapteyn HC 《Physical review letters》2011,106(5):053002
In rare-gas atoms, Auger decay in which an inner-valence shell ns hole is filled is not energetically allowed. However, in the presence of a strong laser field, a new laser-enabled Auger decay channel can open up to increase the double-ionization yield. This process is efficient at high laser intensities, where an ns hole can be filled within a few femtoseconds of its creation. This novel laser-enabled Auger decay process is of fundamental importance for controlling electron dynamics in atoms, molecules, and materials. 相似文献
3.
4.
Auger decay rates of the metastable antiprotonic helium 3,4He
e are calculated. The variational method and solution of coupled differential equations are combined to determine the initial
metastable state wave function. Besides metastable states, the calculation reveals specific short-lived states of the antiprotonic
helium with an essentially different structure of the wave function. An effect of mixture of the wave functions is taken into
account to calculate the decay rate for a few metastable states, which are close in energy to the short-lived ones.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
O. Travnikova C. Miron M. Bssler R. Feifel M.N. Piancastelli S.L. Sorensen S. Svensson 《Journal of Electron Spectroscopy and Related Phenomena》2009,174(1-3):100
The present work aims at characterizing short-lived C1s(−1)π*(1) core-excited states of the OCS molecule based on the analysis of the vibrational fine structure and lineshape profiles of the high-resolution resonant Auger decay spectra recorded at the excitation energies along the C1s→π* resonance in the binding energy region 15–19 eV. Very different behavior in terms of lineshape and resonant enhancement is observed for the , and final states. This is explained by (1) the variation in the C–O bond lengths for the states involved in the electronic relaxation and (2) different contributions in terms of Mulliken population to the molecular orbitals determining the electronic character of the corresponding states. Since the final-state geometries are known from a number of previous experiments and ab initio calculations, the geometry of the C1s(−1)π*(1) intermediate states can be predicted in analogy with e.g. the N2, CO2 and N2O molecules. 相似文献
6.
Q. Luo X.Y. Yu Z.R. Qiu W.L. Li Q. Li J.Y. Zhou 《Applied physics. B, Lasers and optics》2000,70(1):53-56
We report a novel two-channel experimental scheme to record femtosecond amplitude and phase dynamics for dephasing studies. The measurement of free-induction decay in one channel and pulse autocorrelation for the central wavelength of the exciting pulses at the other channel as the reference allows the recording of time-resolved amplitude and phase dynamics of the free-induction decay throughout the dephasing process. The technique is applied to the study of coherent dynamics of the photocarriers in semiconductor GaAs. The observed phase dynamics is well simulated with optical Bloch vector components analysis for the homogeneously broadened two-level model and the experimental and theoretical study is extended for the three-level system. The two-pulse-induced phase spectroscopy should be generally applicable to different kinds of materials by recording the population difference for the two-level system with pulse-induced fluorescence. 相似文献
7.
V.G. Yarzhemsky F.P. Larkins 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,5(2):179-184
The theory of the shapes of Auger decay lines of satellite two-hole-one particle states accompanying photoionization based
on the Green's function method is developed. The lineshapes of Auger decay of satellite states [2
s
2
p
](
1,3
P
)3
s
(
2
P
), [2
s
2
p
](
1
P
)4
s
(
2
P
) and [3
s
3
p
](
3
P
)4
s
(
2
P
) in valence p-photoelectron spectra of Ne and Ar atoms are calculated (hole states are indicated by square brackets throughout). It is
shown that in some cases the Auger lineshapes reproduce the shape of the photoelectron satellite line, but in other cases
Auger line may be narrower then the photoelectron line and may have opposite direction of asymmetry. The theoretical results
are in agreement with experimental low-energy Auger spectra.
Received: 25 May 1998 / Accepted: 2 October 1998 相似文献
8.
9.
Verhoef A. J. Mitrofanov A. V. Nguyen X. T. Krikunova M. Fritzsche S. Kabachnik N. M. Drescher M. Baltuška A. 《Laser Physics》2011,21(7):1270-1274
The cascaded Auger decay following ionization or excitation with 94 eV soft-X-ray pulses from the 3d subshell in krypton has been energy-and-time-resolved for the first time. The decay time of the 4s
−14p
−2
nl → 4p
−3 + e and/or 4s
−14p
−1
nl → 4p
−2 + e transition is measured to be 74 ± 20 fs. Furthermore, our data shows that the electrons with a kinetic energy around 25 eV
(generally assigned as 3d
−1
np → 4s
−2
n′p + e) emitted after core excitation are emitted in a second decay step suggesting an alternative assignment of the form 4s
−2
np 4p
−2 + e. 相似文献
10.
All possible channels of double Auger decay of a 3d vacancy in a Kr atom are investigated using perturbation theory in a basis
of Hartree-Fock wave functions. The energy spectrum of the Auger electrons and the total decay width are calculated. The role
of model decay mechanisms is discussed, along with the importance of taking correlation interactions into account.
Tomsk Polytechnic University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 54–63, October,
1998. 相似文献
11.
S. Parida N. Chandra R. Ghosh 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(3):303-329
The simultaneous emission of two electrons in photoionization, or in the non-radiative
spontaneous decay of an inner-shell vacancy, are two of the best known examples of the
failure of the independent-particle model of atoms and molecules. The later of these
provides also one of the two competitive processes, following inner-shell photoionization,
for producing three flying electrons which can, for example, be used in implementing many
protocols hitherto developed in quantum information. The correlation properties of the
three-particle system consisting of these two electrons plus the photoelectron are
analyzed using methods from quantum information theory. The entanglement of the consequent
tripartite spin-state is shown to be completely independent of the mechanism(s) which may
be responsible for the emission of these three electronic qubits in two different steps in
the absence of spin-orbit interaction. Our analysis shows that the tripartite state formed
in the present case is more like a |W〉 class of states possessing pairwise
entanglement. The experimental characterization of these states is fully achieved merely
by the measurements of the energies of three flying electrons, without requiring any
entanglement witness or other similar protocols hitherto developed in quantum information.
Changes in these entanglement properties of a tripartite state of electronic qubits on the
inclusion of the spin-orbit interaction have also been discussed. 相似文献
12.
13.
14.
S. Parida 《Physics letters. A》2009,373(21):1852-1855
We theoretically show that the process of inner-shell photoionization in an atom A, followed by the spontaneous sequential emission of two Auger electrons, produces various kinds of spin-entangled states of three flying electronic qubits. All properties of these states are completely pre-determined by the total spin quantum numbers of the electronic states of four atomic species (i.e., A, A+∗, A2+∗, A3+) participating in this process in the Russell-Saunders coupling. These tripartite states are readily characterized experimentally by measuring only energies of the three emitted electrons, without requiring any entanglement witness or other such protocols. 相似文献
15.
16.
17.
《Superlattices and Microstructures》1988,4(2):227-232
The origin and characteristics of the cross-interface photoluminescence observed in hydrostatic-pressure-induced, type II GaAs/AlGaAs superlattices is investigated. A low quantum efficiency luminescence feature with an Auger-limited lifetime, as evidenced by the observation of the “hot” Auger electrons recombining across the GaAs direct-gap, was observed. This feature has been found in a set of MOCVD-prepared superlattices, identical, except for the Al-mole-fraction of the barriers. The feature exhibiting Auger recombination is attributed to the recombination of a cross-interface exciton bound to a neutral donor in the AlGaAs. An impurity-bound-exciton seems necessary to explain the over 3-decade purely exponential decays observed in these experiments. 相似文献
18.
利用基于多组态Dirac-Fock理论方法的研究原子结构和性质的程序GRASP92和RATIP以及最新发展的研究光电离和辐射复合过程的程序RERR06,研究了光子能量为947.9 eV时Ne原子的1s光电子谱及其相应的Auger衰变过程.所得结果与其他的理论结果和实验结果符合得很好.通过分析光电离伴随态Ne+1s-12p-1(1,3P)3p的Auger衰变过程可知:3p旁观的Auger跃迁是主要的衰变机制,Ne+1s-12p-1(1P)3p的Auger强度整体上大于Ne+1s-12p-1(3P)3p的Auger强度.同时,也预言了光电离伴随态Ne+1s-12p-1(1,3P)3p产生的Ne+,Ne2+和Ne3+末电离态离子的相对丰度分别为0.02,0.58和0.41.
关键词:
光电离
Auger衰变
多组态Dirac-Fock方法 相似文献
19.
W. Rosenthal 《Solid State Communications》1973,13(8):1215-1218
The strong decrease of lifetime in semiconductors under high doping conditions is discussed. The Auger effect should be responsible for it in both p-type and n-type material. Formulas for the begin of decrease are discussed and the appropriate carrier concentrations are calculated for several III–V compounds. 相似文献