Suppression of correlated electron escape in double ionization in strong laser fields
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Transcript of Suppression of correlated electron escape in double ionization in strong laser fields
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Suppression of correlated electron escape indouble ionization in strong laser fields
B. Eckhardt 1, K. Sacha 2, J. Zakrzewski 2,J. S. Prauzner-Bechcicki 2
1 Philipps-Universitat Marburg,2 Jagiellonian University, Krakow
International Workshop on Atomic PhysicsNovember 26-30, 2007
MPIPKS Dresden
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Plan:
• Selection rules in double ionization of atoms
• Suppression of correlated electron escape in double ionizationof metastable He
• Quantum simulation of double ionization of metastable He
• Double ionization of molecules
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Correlated electron escape:T. Weber et al., Nature 405, 658 (2000)
Double ionization of Ar atomslaser pulses: 800 nm, 220 fs, 3.8 · 1014 W/cm2
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Maulbetsch & Briggs selection rules:F. Maulbetsch & J. S. Briggs, JPB 28, 551 (1995)
〈~k1, ~k2|T |ψ〉 =∑
αLMS
〈~k1, ~k2|αLMS〉〈αLMS |T |ψ〉
(M + S) odd ⇒ 〈~k1, ~k2|αLMS〉 = 0
if k1 = k2, θ1 = θ2 and |φ1 − φ2| = π.
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Maulbetsch & Briggs selection rules:F. Maulbetsch & J. S. Briggs, JPB 28, 551 (1995)
〈~k1, ~k2|T |ψ〉 =∑
αLMS
〈~k1, ~k2|αLMS〉〈αLMS |T |ψ〉
(M + S) odd ⇒ 〈~k1, ~k2|αLMS〉 = 0
if k1 = k2, θ1 = θ2 and |φ1 − φ2| = π.
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Suppression of correlated electron escape:Eckhardt et al., to appear in PRA 76
For strong field multiphoton double ionization:
T = U = P exp(−i
∫ Td
0 dtH(t)/~)
H =~p2
1+~p22
2 − 2r1− 2
r2+ 1
|~r1−~r2| + F (t)(z1 + z2)
⇒ M + S = const
For |ψ〉 being the metastable state of He where M = 0 and S = 1:
(M + S) odd ⇒ 〈~k1, ~k2|U|ψ〉 = 0 if:
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Suppression of correlated electron escape:Eckhardt et al., to appear in PRA 76
For strong field multiphoton double ionization:
T = U = P exp(−i
∫ Td
0 dtH(t)/~)
H =~p2
1+~p22
2 − 2r1− 2
r2+ 1
|~r1−~r2| + F (t)(z1 + z2)
⇒ M + S = const
For |ψ〉 being the metastable state of He where M = 0 and S = 1:
(M + S) odd ⇒ 〈~k1, ~k2|U|ψ〉 = 0 if:
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Suppression of correlated electron escape:Eckhardt et al., to appear in PRA 76
For strong field multiphoton double ionization:
T = U = P exp(−i
∫ Td
0 dtH(t)/~)
H =~p2
1+~p22
2 − 2r1− 2
r2+ 1
|~r1−~r2| + F (t)(z1 + z2)
⇒ M + S = const
For |ψ〉 being the metastable state of He where M = 0 and S = 1:
(M + S) odd ⇒ 〈~k1, ~k2|U|ψ〉 = 0 if:
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Symmetric subspace:Sacha & Eckhardt, PRA 63 043414 (2001)
H =p2
1 + p22
2− 2
r1− 2
r2+
1
|r1 − r2|+ F (t)(z1 + z2)
z1 = z2 = zx1 = −x2 = x
⇒ V (x , z ; t) = − 4√x2 + z2
+1
2|x |+ 2F (t)z
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Reduction of the dimensionality:Eckhardt & Sacha, JPB 39 3865 (2006);
Prauzner-Bechcicki et al., PRL 98, 203002 (2007)
the present model V (r1, r2): the aligned electron model V (r1, r2):
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Reduction of the dimensionality:Eckhardt & Sacha, JPB 39 3865 (2006);
Prauzner-Bechcicki et al., PRL 98, 203002 (2007)
the present model V (r1, r2):
the aligned electron model V (r1, r2):
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Reduction of the dimensionality:Eckhardt & Sacha, JPB 39 3865 (2006);
Prauzner-Bechcicki et al., PRL 98, 203002 (2007)
the present model V (r1, r2): the aligned electron model V (r1, r2):
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Quantum simulations:Eckhardt et al., to appear in PRA 76
800 nm, single cycle pulse, F = 0.15 a.u.
∆p = 0.07 a.u.
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Quantum simulations:Eckhardt et al., to appear in PRA 76
800 nm, single cycle pulse, F = 0.15 a.u.
∆p = 0.07 a.u.
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Quantum simulations:Eckhardt et al., to appear in PRA 76
800 nm, single cycle pulse, F = 0.15 a.u.
∆p = 0.07 a.u.
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Double ionization of N2 and O2 molecules:
N2: O2:
Eremina et al., PRL 92, 173001 (2004)
N2:
Zeidler et al., PRL 95, 203300 (2005)
〈~k1, ~k2|T |ψ〉 =∑
αLMS
〈~k1, ~k2|αLMS〉〈αLMS |T |ψ〉
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Double ionization of N2 and O2 molecules:
N2: O2:
Eremina et al., PRL 92, 173001 (2004)
N2:
Zeidler et al., PRL 95, 203300 (2005)
〈~k1, ~k2|T |ψ〉 =∑
αLMS
〈~k1, ~k2|αLMS〉〈αLMS |T |ψ〉
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Double ionization of N2 and O2 molecules:
N2: O2:
Eremina et al., PRL 92, 173001 (2004)
N2:
Zeidler et al., PRL 95, 203300 (2005)
〈~k1, ~k2|T |ψ〉 =∑
αLMS
〈~k1, ~k2|αLMS〉〈αLMS |T |ψ〉
Starting point Selection rules Suppression. . . Symmetric subspace Quantum simulations Diatomic molecules Conclusions
Conclusions:
• We have analyzed suppression of correlated electron escape indouble ionization of metastable He atoms by strong laserpulses
• In double ionization of molecules one may expect the similarsuppression, e.g. for O2 oriented along the polarization axis.