Multiphoton microwave ionization of Li Rydberg atoms Josh Gurian - - PowerPoint PPT Presentation

▶
multiphoton microwave ionization of li rydberg atoms
SMART_READER_LITE
LIVE PREVIEW

Multiphoton microwave ionization of Li Rydberg atoms Josh Gurian - - PowerPoint PPT Presentation

Jun 17, 2023 223 likes •665 views

Introduction Experimental Setup Results Multiphoton microwave ionization of Li Rydberg atoms Josh Gurian Professor Thomas Gallagher April 28, 2008 J. Gurian Multiphoton MW Ionization Introduction Experimental Setup Results Outline

slide-1
SLIDE 1

Introduction Experimental Setup Results

Multiphoton microwave ionization of Li Rydberg atoms

Josh Gurian Professor Thomas Gallagher April 28, 2008

  • J. Gurian

Multiphoton MW Ionization

slide-2
SLIDE 2

Introduction Experimental Setup Results

Outline

Introduction Experimental Setup kHz Dye Laser Project Experimental Apparatus Results Ionization Steps Final State Distribution

  • J. Gurian

Multiphoton MW Ionization

slide-3
SLIDE 3

Introduction Experimental Setup Results

Rydberg atom overview

◮ W = −1

2n2

◮ r ∝ n2 ◮ Lifetime ∝ n3 ◮ ωkepler ∝ 1/n3 ◮ Vcoulomb = − 1 |z|

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

  • J. Gurian

Multiphoton MW Ionization

slide-4
SLIDE 4

Introduction Experimental Setup Results

Rydberg atom overview

◮ W = −1

2n2

◮ r ∝ n2 ◮ Lifetime ∝ n3 ◮ ωkepler ∝ 1/n3 ◮ V = − 1 |z| + Ez

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

  • J. Gurian

Multiphoton MW Ionization

slide-5
SLIDE 5

Introduction Experimental Setup Results

Field Ionization

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

◮ V = − 1 |z| + Ez ◮ dV dz = 0

  • J. Gurian

Multiphoton MW Ionization

slide-6
SLIDE 6

Introduction Experimental Setup Results

Field Ionization

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

◮ V = − 1 |z| + Ez ◮ dV dz = 0 ◮ V = −2

√ E

  • J. Gurian

Multiphoton MW Ionization

slide-7
SLIDE 7

Introduction Experimental Setup Results

Field Ionization

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

◮ V = − 1 |z| + Ez ◮ dV dz = 0 ◮ V = −2

√ E

◮ E = W 2

4

  • J. Gurian

Multiphoton MW Ionization

slide-8
SLIDE 8

Introduction Experimental Setup Results

Field Ionization

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

◮ E = W 2

4

◮ W = −1 2n2 + 3 2nkE

  • J. Gurian

Multiphoton MW Ionization

slide-9
SLIDE 9

Introduction Experimental Setup Results

Field Ionization

  • 6
  • 2

2

  • 10
  • 6
  • 2

2 6 10 z V

◮ E = W 2

4

◮ W = −1 2n2 + 3 2nkE ◮ E =

1 9n4

  • J. Gurian

Multiphoton MW Ionization

slide-10
SLIDE 10

Introduction Experimental Setup Results

Scaled Frequency

Important characteristic: ω0 = ω ωkepler = ωn3 Previous work for ω0 ≤ 1:

◮ van Leeuwen et al., PRL 55 (1985) ◮ Jensen et al., PRL 62 (1989) ◮ Pillet et al., PRA 30 (1984) ◮ Noel et al., PRA 62 (2000)

  • J. Gurian

Multiphoton MW Ionization

slide-11
SLIDE 11

Introduction Experimental Setup Results

Microwave Ionization

Pillet et al., PRA 30 (1984)

  • J. Gurian

Multiphoton MW Ionization

slide-12
SLIDE 12

Introduction Experimental Setup Results

Photoionization limit?

What happens as we approach the photoionization limit, when ω0 → n?

  • J. Gurian

Multiphoton MW Ionization

slide-13
SLIDE 13

Introduction Experimental Setup Results

Cartoon

  • 300
  • 250
  • 200
  • 150
  • 100
  • 50

Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon

  • J. Gurian

Multiphoton MW Ionization

slide-14
SLIDE 14

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon

  • J. Gurian

Multiphoton MW Ionization

slide-15
SLIDE 15

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-16
SLIDE 16

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm 0.67 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-17
SLIDE 17

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm 0.67 mV/cm 1.83 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-18
SLIDE 18

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm 0.67 mV/cm 1.83 mV/cm 3.8 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-19
SLIDE 19

Introduction Experimental Setup Results

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm 0.67 mV/cm 1.83 mV/cm 3.8 mV/cm 6.6 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-20
SLIDE 20

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Outline

Introduction Experimental Setup kHz Dye Laser Project Experimental Apparatus Results Ionization Steps Final State Distribution

  • J. Gurian

Multiphoton MW Ionization

slide-21
SLIDE 21

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Coherent Evolution-30 Nd:YLF Laser

  • 100

100 200 300 400 500 600 700 Normalized photodiode signal (arb) Relative time (ns)

  • J. Gurian

Multiphoton MW Ionization

slide-22
SLIDE 22

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Coherent Evolution-30 Nd:YLF Laser

◮ 1st Pulse: 20ns ◮ 2nd Pulse: 35ns ◮ 3rd Pulse: 41ns

  • 100

100 200 300 400 500 600 700 Normalized photodiode signal (arb) Relative time (ns) First Pulse Second Pulse Third Pulse

  • J. Gurian

Multiphoton MW Ionization

slide-23
SLIDE 23

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Laser Setup

Pump Laser PC PC PBS

❅ ❅ ❅

PBS

  • Dump

BS

  • BS ❅

❅ ❅

Dye Laser Dye Laser Dye Laser Amp

❅ ❅ ❅ ❅

  • ❅

❅ ❅ ❅ ❅ ❅ ❅ ❅

  • ❅

❅ ❄ ✲ ❄ ❄ ✛ ✻ ✻ ✲✻ ✻ ✛ ✛ ✛ ✻ ✛ ❄ ✛ ✻ ✛ ❄ ✻

1 2 3

✻ ✻ ✛ ✛

  • J. Gurian

Multiphoton MW Ionization

slide-24
SLIDE 24

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Experimental Setup

  • J. Gurian

Multiphoton MW Ionization

slide-25
SLIDE 25

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Experimental Setup

  • J. Gurian

Multiphoton MW Ionization

slide-26
SLIDE 26

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Timing

200 400 600 800 1000 time (ns) 0-2V/cm Laser Pulses 100-500 ns MW Pulse Field Pulse

  • J. Gurian

Multiphoton MW Ionization

slide-27
SLIDE 27

Introduction Experimental Setup Results kHz Dye Laser Project Experimental Apparatus

Experimental Setup

  • J. Gurian

Multiphoton MW Ionization

slide-28
SLIDE 28

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Outline

Introduction Experimental Setup kHz Dye Laser Project Experimental Apparatus Results Ionization Steps Final State Distribution

  • J. Gurian

Multiphoton MW Ionization

slide-29
SLIDE 29

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Cartoon

  • 107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

17.85 Normalized electron signal (arb) Binding energy (GHz) MW Ionization Cartoon No MW 0.11 mV/cm 0.67 mV/cm 1.83 mV/cm 3.8 mV/cm 6.6 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-30
SLIDE 30

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Microwave Ionization Steps - Powers

  • 178.5 -160.65 -142.8 -124.95 -107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

Normalized electron signal (arb) Binding energy (GHz) 200ns MW pulse at 17.850GHz 0.125 V/cm 0.25 V/cm 0.5 V/cm 1 V/cm

  • J. Gurian

Multiphoton MW Ionization

slide-31
SLIDE 31

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Pulsewidths

  • 178.5 -160.65 -142.8 -124.95 -107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

Normalized electron signal (arb) Binding energy (GHz) Various MW pulsewidths at 17.850GHz, 1 V/cm 100ns 200ns 300ns 400ns 500ns

  • J. Gurian

Multiphoton MW Ionization

slide-32
SLIDE 32

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Ionization Rate

0.01 0.1 1 200 400 600 800 1000 1200 1400 Relative remaining population (arb) pulsewidth (ns) 1.5 MW photons from ionization limit 1 V/cm

  • 2 db
  • 4 db
  • 6db
  • 8db
  • 10db
  • J. Gurian

Multiphoton MW Ionization

slide-33
SLIDE 33

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Theoretical Predictions

Γexp(n ≈ 360, E ≈ 0.8V/cm, 50ns) = 5.6 × 106s−1 Hoogenraad and Noordam, PRA 57 (1998): < n|r|n′ >≈ 0.4108n−3/2n′−3/2 ω5/3 We can calculate the ionization rate: Γ = 2π| < n|r|ǫ > E|2 Γ(n = 360, E = 0.8V/cm) = 8.2 × 107s−1 Γ(n = 360, E = 0.2V/cm) = 5.6 × 106s−1

  • J. Gurian

Multiphoton MW Ionization

slide-34
SLIDE 34

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Bias Field

  • 178.5 -160.65 -142.8 -124.95 -107.1
  • 89.25
  • 71.4
  • 53.55
  • 35.7
  • 17.85

Normalized electron signal (arb) Binding energy (GHz) Bias voltages on top plate for 200ns MW pulse at 17.850 GHz, 1 V/cm 0 V/cm 8.5 mV/cm 17 mV/cm 85 mV/cm

  • J. Gurian

Multiphoton MW Ionization

slide-35
SLIDE 35

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Final State Distribution

E = 1/9n4

200 400 600 800 1000 time (ns) Laser Pulses Field Pulse

  • J. Gurian

Multiphoton MW Ionization

slide-36
SLIDE 36

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Final State Distribution

Final State Distribution without MW pulse

  • 214.2-196.35-178.5-160.65-142.8-124.95-107.1 -89.25 -71.4 -53.55 -35.7 -17.85

Binding energy (GHz) 50 100 150 200 250 300 350 400 Relative Time (ns)

  • J. Gurian

Multiphoton MW Ionization

slide-37
SLIDE 37

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Final State Distribution

E = 1/9n4

200 400 600 800 1000 time (ns) 1 V/cm Laser Pulses 200 ns MW Pulse Field Pulse

  • J. Gurian

Multiphoton MW Ionization

slide-38
SLIDE 38

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Final State Distribution

Final State Distribution with 200ns 17.85 GHz 1 V/cm MW pulse

  • 214.2-196.35-178.5-160.65-142.8-124.95-107.1 -89.25 -71.4 -53.55 -35.7 -17.85

Binding energy (GHz) 50 100 150 200 250 300 350 400 Relative Time (ns)

  • J. Gurian

Multiphoton MW Ionization

slide-39
SLIDE 39

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Summary

◮ Introduction to Rydberg field ionization ◮ Overview of microwave ionization ◮ Experiment setup ◮ First results for microwave multiphoton ionization of

Rydberg Li atoms

  • J. Gurian

Multiphoton MW Ionization

slide-40
SLIDE 40

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Thanks

Professor Tom Gallagher

  • Dr. Haruka Maeda
  • Dr. Ed Shuman

Paul Tanner Jianing Han Jirakan Nunkaew Don Norum Hyunwook Park National Science Foundation

  • J. Gurian

Multiphoton MW Ionization

slide-41
SLIDE 41

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Final State Distribution Comparison

Final State Distribution without MW pulse

  • 214.2-196.35-178.5-160.65-142.8-124.95-107.1 -89.25 -71.4 -53.55 -35.7 -17.85

Binding energy (GHz) 50 100 150 200 250 300 350 400 Relative Time (ns) Final State Distribution with 200ns 17.85 GHz 10dbm MW pulse

  • 214.2-196.35-178.5-160.65-142.8-124.95-107.1 -89.25 -71.4 -53.55 -35.7 -17.85

Binding energy (GHz) 50 100 150 200 250 300 350 400 Relative Time (ns)

  • J. Gurian

Multiphoton MW Ionization

slide-42
SLIDE 42

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Dye laser output

0.2 0.4 0.6 0.8 1 20 40 60 80 100 Normalized photodiode signal (arb) Time (nanoseconds) 671nm Dye Laser Pulse 813nm Dye Laser Pulse 615nm Dye Laser Pulse

  • J. Gurian

Multiphoton MW Ionization

slide-43
SLIDE 43

Introduction Experimental Setup Results Ionization Steps Final State Distribution

Atomic Conductance

Schelle, Delande, and Buchleitner:

  • J. Gurian

Multiphoton MW Ionization