molecular tunneling ionization and molecular alignment
DESCRIPTION
Molecular Tunneling Ionization and Molecular Alignment. X. M. Tong, Z. X. Zhao and C. D. Lin Physics Department, Kansas State University, Manhattan KS 66506. email: [email protected] http://phys.ksu.edu/~xmtong. Molecular Tunneling Ionization. Motivation: - PowerPoint PPT PresentationTRANSCRIPT
Molecular Tunneling Ionization and Molecular Alignment
X. M. Tong, Z. X. Zhao and C. D. Lin
Physics Department,Kansas State University, Manhattan KS 66506
email: [email protected] http://phys.ksu.edu/~xmtong
• Motivation:• Ionization; tunneling & multiphoton;• ADK (Ammosov, Delone and Krainov) model;• Experimental observations.
• Theoretical Method:• Molecular orbital at asymptotical region;• Tunneling ionization;• How to compare with experiments?
• Results and Discussion• D2/Ar, N2/Ar, O2/Xe, CO/Kr• S2/Xe, SO/Xe, NO/Xe• F2/Ar
Molecular Tunneling Ionization
Tunneling Ionization
Multiphoton Ionization:
Keldysh parameter
Atoms or Molecules in an Intense Laser Field
Ionization of N2 and Ar
30 fs: Guo et al., PRA 58 (1998) R4271. 100 fs : DeWitt et al., PRL 87 (2001) 153001.
Ip
N2: 15.58 eVAr: 15.76 eV
30 fs: Guo et al., PRA 58 (1998) R4271. 200 fs : Talebpour et al., JPB 29 (1996) L677.
Interference Model:Muth-Bohm et al., PRL 85 (2000) 2280.Failed for D2, F2
Effective Charge:Guo, PRL 85 (2000) 2276.
Ip
O2: 12.36 eVXe: 12.13 eV
Ionization of O2 and Xe
Ionization supression
W.P.T.I.
Atomic Tunneling Ionization
Atomic Tunneling Ionization
Atomic Tunneling Ionization
W.P.T.I.
F
Molecular Tunneling Ionization
A1A2
A3
Molecular Tunneling Ionization
3.5x1014 W/cm2
Ionization Rates of H2+ in a Static Field
F
H2+
z
Saenz, PRA 61(2000) 051402.
Ionization Rates of H2
F
H2
z
Ratio of Ionization Rates for N2:Ar and O2:Xe
F
Tunneling Ionization for Oriented Molecules
X1013 W/cm2
Ionization for Oriented N2 Molecules
X1013 W/cm2
F
Ionization for Oriented O2 Molecules
z
r
How to Compare with Experiments ?
D2/Ar
Ionization Rate, Probability and Signal
D2 Energy Potential
Molecular Vibration Effect
30 fs: Guo et al., PRA 58 (1998) R4271. 100 fs : DeWitt et al., PRL 87 (2001) 153001.
N2/Ar
Ip
N2: 15.58 eVAr: 15.76 eV
30 fs: Guo et al., PRA 58 (1998) R4271. 200 fs : Talebpour et al., JPB 29 (1996) L677.
O2/Xe
Ip
O2: 12.36 eVXe: 12.13 eV
Expt: Wells et al., PRA 66 (2002) 013409.
Ip
D2: 15.47+0.8 eVAr: 15.76 eV
D2/Ar
Expt: Wells et al., PRA 66 (2002) 013409.
Ip
CO: 14.01 eVKr: 14.00 eV
CO/Kr
Expt: 100 fs : DeWitt et al., PRL 87 (2001) 153001.
Ip
F2: 15.70 eVAr: 15.76 eV
F2/Ar
Ip
NO: 9.26 eVS2: 9.36 eVSO: 10.29 eVXe: 12.13 eV
NO/Xe, S2/Xe and SO/Xe
Expt: Wells et al., PRA 66 (2002) 013409.Xe Expt: Guo et al., PRA 58 (1998) R4271.
NO and Xe
Expt: Wells et al., PRA 66 (2002) 013409.Xe Expt: Guo et al., PRA 58 (1998) R4271.
S2 and Xe
Expt: Wells et al., PRA 66 (2002) 013409.Xe Expt: Guo et al., PRA 58 (1998) R4271.
SO and Xe
A1A2
A3
Summary
• Develop a molecular tunneling ionization theory;• Study the diatomic molecular ionization;• Extend to triatomic molecules;• Different suppression mechanisms.
Summary
The full paper can be downloaded fromhttp://www.phys.ksu.edu/~xmtong/pub.html
(2) Molecular Alignment
Fq
(a) Angular dependent ionization signal; (b) How to Align a molecule.
Molecular Alignment in laser field
J. Ortigoso et al., JCP110,3870
Short pulse: revival;Long pulse: No
Molecular Alignment
Initial: Random Kick:
Deposit J
Revival:
Molecular Alignment
F
Molecular Alignment
O2: Wjm = 1 (even J) or 0 (odd J)N2: Wjm = 1/3 (even J) or 2/3 (odd J)
Kick or Push ?
Pulse intensity 2x1013 W/cm2
F t
N2: (2x1013 : 8x1013)
Revival
O2: (2x1013 : 4x1013)
Summary
(a) Optimized revival can be achieved with a fixed laser intensity;(b) 10% to 20% enhancement for O2, and(c) 20% to 60% enhancement for N2;(d) maximum enhancement when the two field parallel.
Summary