Single-Photon Atomic Cooling - Raizen Lab - The University of ...

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differential pumping tube glass-to-metal seal glass cell composite piece a) b) c) differential pumping tube to all metal valve Rb reservoir all metal valve composite piece Figure 3.2: Views of the upper chamber. a) The glass cell connects to the composite piece through a glass-to-metal seal. The differential pumping tube is also attached to the composite piece. b) Schematic of the differential pumping tube and composite piece. The CF flange on the right connects to an all metal valve in the experiment. c) The all metal valve connects to the Rb reservoir. attached to the middle chamber. Second, the differential pumping tube is welded to the composite piece such that the only connection between the upper and lower chamber is through this tube. Finally, a 1/2 ′′ tube is welded to the side of the nipple portion of the composite piece and serves as a path to introduce rubidium into our vacuum system. A 2-3/4 ′′ flange is welded to the end of the 1/2 ′′ tube connected to the side of the nipple. The flange is attached to a 2-1/2 ′′ all metal valve from 88
Nor-Cal Products Inc. (AMV-1502-CF). Attached to the metal valve via a zero length reducer is a 1-1/3 ′′ tee. Both sides of the tee have 1/2 ′′ copper pinch-off tubes (Huntington, CPT-133-050) attached. One of these was used as a connection port to a turbo-pump station during the vacuum bakeout. It was sealed when the bakeout was complete. The other pinch-off tube houses a glass ampule containing ≈ 200 mg of Rb (ESPI, purity 3N5). The ampule was cracked from the outside by squeezing the copper tube with pliers when the pump down was complete but while the chamber was still attached to the turbo-pump station. The ≈ 200 mg piece of solid Rb contains the isotope of interest, 87 Rb, at the natural abundance level of ≈ 28%. One may wonder what role, if any, the more abundant isotope 85 Rb played in our experiment. The isotopic shift is sufficiently large so that 85 Rb is not resonant with the laser beams tuned near the D2 transition in 87 Rb. This means that 85 Rb is not captured in our MOTs. However, the two isotopes can collide resulting in magnetic trap loss. The combined vapor pressure of both isotopes determines the collision rate, and hence the lifetime of atoms in the magnetic trap. In this sense the presence of 85 Rb has a somewhat detrimental effect. The pressure in the upper chamber is determined by the vapor pressure of solid rubidium at room temperature which can be approximated by Eq. 2.1 log10Pv = 2.881 + 4.857 − 4215 T . The experiment resides in a room servo-looped to maintain a temperature 89
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Copyright by Gabriel Noam Price 200
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Single-Photon Atomic Cooling by Gab
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Acknowledgments First, I would like
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Rubidium group when I first joined.
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Single-Photon Atomic Cooling Public
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2.5.2.4 Magneto-Optical Trap . . .
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List of Tables 2.1 87 Rb Physical P
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3.1 Vacuum Chamber . . . . . . . .
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Chapter 1 Introduction This chapter
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the momentum kicks due to absorptio
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samples by allowing for very long i
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Figure 1.2: The energy level struct
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quency regime [19]. This then led t
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Figure 1.4: Depiction of a simple,
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demonstrates the cooling power of a
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a) b) c) external potential one-way
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worked on by Brillouin [27-29], ide
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the atomic ensemble. Not surprising
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are untrappable. The SI unit for en
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the atomic transition and is called
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2.1 Rubidium Rubidium (Rb) is an al
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constant which is given by α = e2
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only one value of J is possible fro
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the latter of which only applies to
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Figure 2.1: 87 Rb D2 Transition Hyp
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Pluging Eq. 2.18 into this Hamilton
Page 53 and 54: Following the same logic leads to a
Page 55 and 56: gF = −1/2 using the approximate e
Page 57 and 58: mize their energy in high magnetic
Page 59 and 60: If we now consider the field from t
Page 61 and 62: where P is in torr. The lifetime of
Page 63 and 64: component of the dipole oscillation
Page 65 and 66: maxima. Our experiment makes extens
Page 67 and 68: atoms its wavefunction Ψ(t) is typ
Page 69 and 70: In this equation we let H = H0 + Hc
Page 71 and 72: The significance of Isat is that at
Page 73 and 74: Δ ω =ω−Δ ω =ω−Δ Δ
Page 75 and 76: where I/Isat ≪ 1 has been assumed
Page 77 and 78: λ λ Figure 2.9: The Sisyphus cool
Page 79 and 80: process repeats. If however, it dec
Page 81 and 82: σ σ σ Figure 2.10: Geomet
Page 83 and 84: to vary linearly with position alon
Page 85 and 86: 0, ±1 and ∆mF = 0, ±1, allow ex
Page 87 and 88: this figure only the relevant hyper
Page 89 and 90: D2 transition in 87 Rb has a natura
Page 91 and 92: 2.7.2 Saturation Absorption Spectro
Page 93 and 94: ground state depletion due to the p
Page 95 and 96: oadened background can be removed f
Page 97 and 98: where n is the number density of at
Page 99 and 100: where σ 2 c = σ 2 2 kBTt n + m .
Page 101 and 102: Chapter 3 Experimental Apparatus Th
Page 103: Figure 3.1: The vacuum chamber duri
Page 107 and 108: and monitor the necessary vacuum le
Page 109 and 110: 3.1.3 Lower Chamber The lower chamb
Page 111 and 112: a) top ridge 1 cm b) metal jacket h
Page 113 and 114: to the appropriate frequency throug
Page 115 and 116: plexiglass cover piezo U stack grat
Page 117 and 118: λ Figure 3
Page 119 and 120: Voltage a b c d e f Frequency Figur
Page 121 and 122: eams. For example the MOT and optic
Page 123 and 124: λ Figure 3.12: The slave lasers
Page 125 and 126: λ λ λ
Page 127 and 128: λ λ λ λ
Page 129 and 130: needed when forming a MOT or optica
Page 131 and 132: master laser is dithered at 20 kHz.
Page 133 and 134: λ λ
Page 135 and 136: Output Power > 10 W Wavelength 532
Page 137 and 138: labeled 1, 2 and 3 in the Fig. 3.21
Page 139 and 140: λ λ λ λ
Page 141 and 142: process. The two coils are arranged
Page 143 and 144: 19) connected in parallel. This arr
Page 145 and 146: 3.4.2 Horizontal Imaging The horizo
Page 147 and 148: Chapter 4 Single-Photon Atomic Cool
Page 149 and 150: 1 s, after which time ∼ 10 8 87 R
Page 151 and 152: (a) x z magnetically trapped atoms
Page 153 and 154: h x z magnetically trapped atoms y
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z y x magnetically trapped atoms cr
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Figure 4.5: The effective potential
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depopulation present and it indicat
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numbers sufficiently large to quant
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μ μ μ
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the potential landscape due to the
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Figure 4.12: The number of atoms lo
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Figure 4.13: Incremental atom captu
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netic trap and transfer into the op
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temperature TB of atoms loaded into
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used to construct it into the remai
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μ μ μ Figure 4.18: Side view of
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Figure 4.20: Geometry of the optica
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could potentially have undergone th
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detunings. The result of scattering
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are switched off causing non-optica
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Figure 4.25: Number (■) and tempe
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traps. If we model the ensembles in
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Figure 4.26: Radius of the atomic c
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atoms were removed from the magneti
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trappable |F = 1,mF = −1〉 state
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the short lived 2p state. Atoms whi
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Bibliography [1] R. Frisch, “Expe
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[15] C. C. Bradley, C. A. Sackett,
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[31] E.T. Jaynes, “Information th
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[49] J. Ye, S. Swartz, P. Jungner,
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[66] J.P. Gordon and A. Ashkin, “
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[85] C.-S. Chuu, Direct Study of Qu
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adicals,” Phys. Rev. Lett. 94, 02
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