Evolution operator calculation and transition probability study of molecules interacting with an electromagnetic field

2001 ◽  
Author(s):  
J. L. Paz ◽  
J. Recamier
Keyword(s):  
Electromagnetic Field ◽  
Evolution Operator ◽  
Transition Probability ◽  
Operator Calculation

scholarly journals Counterdiabatic Hamiltonians for multistate Landau-Zener problem

2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Kohji Nishimura ◽  
Kazutaka Takahashi
Keyword(s):  
Time Evolution ◽  
Evolution Operator ◽  
Transition Probability ◽  
Transverse Field ◽  
Integration Contour ◽  
Curvature Condition ◽  
Spin Models ◽  
Time Evolution Operator ◽  
Zero Curvature ◽  
Asymptotic Forms

We study the Landau–Zener transitions generalized to multistate systems. Based on the work by Sinitsyn et al. [Phys. Rev. Lett. 120, 190402 (2018)], we introduce the auxiliary Hamiltonians that are interpreted as the counterdiabatic terms. We find that the counterdiabatic Hamiltonians satisfy the zero curvature condition. The general structures of the auxiliary Hamiltonians are studied in detail and the time-evolution operator is evaluated by using a deformation of the integration contour and asymptotic forms of the auxiliary Hamiltonians. For several spin models with transverse field, we calculate the transition probability between the initial and final ground states and find that the method is useful to study nonadiabatic regime.

scholarly journals Infrared dynamics in (2+1) dimensions

1998 ◽  
Vol 76 (1) ◽  
pp. 69-76 ◽  
Author(s):  
J L Boldo ◽  
B M Pimentel ◽  
J L Tomazelli
Keyword(s):  
Electromagnetic Field ◽  
Quantum Electrodynamics ◽  
Evolution Operator ◽  
Infrared Region ◽  
Current Operator ◽  
Scattering Operator ◽  
Coulomb Phase ◽  
Free Fields ◽  
Faddeev Model ◽  
Fermion Current

In this work we study the asymptotic behavior of (2+1)-dimensional quantum electrodynamics in the infrared region. We show that an appropriate redefinition of the fermion current operator leads to an asymptotic evolution operator that contains a divergent Coulomb phase factor and a contribution from the electromagnetic field at large distances, factored from the evolution operator for free fields, and we conclude that the modified scattering operator maps two spaces of coherent states of the electromagnetic field, as in the Kulish–Faddeev model for QED (quantum electrodynamics) in four space-time dimensions. PACS No. 11.10Kk, 11.55m

Quantized form of electron–nucleus interaction in laser fields

2002 ◽  
Vol 80 (10) ◽  
pp. 1115-1120 ◽  
Author(s):  
Péter Kálmán ◽  
Tamás Bükki
Keyword(s):  
Electromagnetic Field ◽  
Coherent State ◽  
Laser Field ◽  
Electromagnetic Interaction ◽  
Transition Probability ◽  
Vacuum State ◽  
Combined Processes ◽  
Nucleus Interaction ◽  
Photon Exchange ◽  
Quantized Electromagnetic Field

A general formalism for the treatment of electron–nucleus laser-combined processes is presented in a quantized manner. The laser is described by a coherent state in one mode of the quantized electromagnetic field. The system is composed of one electron and A nucleons and it is handled with A + 1 particle quantum mechanics. As a first step, the coherent state is transformed into the vacuum state, while a classical external field corresponding to the laser field arises. The interaction with the laser beam is taken into account by transforming the system into an oscillating frame, called Henneberger picture, while the electron–nucleus electromagnetic interaction is handled as photon exchange via quantized electromagnetic field and in the second order of perturbation theory. A general expression for the transition probability per unit time is given in the l photonic case.PACS Nos.: 23.20Nx, 32.80Wr

Comparison of high- and low-frequency electromagnetic field analysis

1993 ◽  
Vol 3 (3) ◽  
pp. 363-371 ◽  
Author(s):  
A. Konrad ◽  
I. A. Tsukerman
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Field Analysis

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

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