Robert E. Wagner

Sophomore

Intense Laser Physics Theory Unit

Illinois State University

Cycloatoms and high order harmonics in moderate intense

laser fields

Support: NSF, Res. Corp., and ISU Honors Program

Laser

Magnetic field

d

dt

mv

1 v2

c2

qE

r , t q

c

v

B o

B

r , t V

r

Relativity without super-strong lasers?

0.20

0.40

0.60

0.80

1.0

0.003 0.004 0.005 0.006

Maximum speed v/c for each

L 0.0043a.u.

E0 0.0500a.u.

non-relativistic

relativistic

L

R.E. Wagner, Q. Su and R. Grobe, Phys. Rev. Lett. 84, 3282 (2000).

Non-relativistic Relativistic

Orbits stayin phase

Orbits dephaserelativistically

Time(in 2L

75

150

500

0

y

x

Cycloatom dynamics=L

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QuickTime™ and aGIF decompressor

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relativistic (exact) dephasing model

Time

75

150

500

0

Relativistic dephasing model

x(t) x vx

sin t vy

cos t 1

2 2

cos( t

cos t

y(t) y vy

sin t vx

cos(t) 1

2 2

1

sin t 1

sin t

replace (V0)

Steady state spatial electron distributionsMultiple resonances

Fractional resonances ≈ 1/2 L ≈ 1/3 L

≈ L

≈ 2 L

≈ 3 L

0

0.4

0.8

1.2

0 0.1 0.2 0.3 0.4 0.5

[a.u.]

= L

= L/2

= 2L

= 3L

= 3L/2

= 2L/3

= L/3

=

L/4

=

L/5

P.J. Peverly, R.E. Wagner, Q.Su and R. Grobe, Las. Phys. 10, 303 ( 2000).Q. Su, R.E. Wagner, P.J. Peverly, and R. Grobe, Front. Las. Phys. p. 117-123 (Springer, 2000).

Cycloatom dynamics=1/2 L

QuickTime™ and aGIF decompressor

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QuickTime™ and aGIF decompressor

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100

102

104

0 4 8 12 16 200 4 8 12 16 20

100

102

104

Scattered light spectra

non-relativistic relativistic

R.E. Wagner, et al, PRA 60, 3233 (1999)

Quantum Mechanical Cycloatoms?

it

ic A V(r)Dirac

Liouville

J. Braun, Q. Su and R. Grobe, PRA 59, 604 (1999)

P. Peverly, R. Wagner, Q. Su and R. Grobe, Las Phys. 10, 303 (2000)

H c4 c2 (p A / c)2 V(r)

t

(x, p,t) H

x

p

H

p

x

DiracLiouville

Confirmed: Dirac Cycloatoms

P. Krekora, R. Wagner, Q. Su and R. Grobe, PRA, submitted

Summary• Cycloatoms reveal new relativistic phenomena

• Novel resonances => possible experiments

[1] R.E. Wagner, Q. Su and R. Grobe, Phys. Rev. Lett. 84, 3282 (2000).[2] R.E. Wagner, Q. Su, and R. Grobe, Phys. Rev. A 60, 3233, 1999.[3] R.E. Wagner, P.J. Peverly, Q. Su and R. Grobe, Phys. Rev. A 61, 35402(2000).[4] P.J. Peverly, R.E. Wagner, Q.Su and R. Grobe, Las. Phys. 10, 303 ( 2000).[5] P. Krekora, R.E. Wagner, Q. Su and R. Grobe, PRA, submitted.[6] Q. Su, R.E. Wagner, P.J. Peverly, and R. Grobe, Front. Las. Phys. p. 117-123 (Springer, 2000).

www.phy.ilstu.edu/ILP

Undergraduate Student travel grant (DAMOP)