Measuring Polarizability with an Atom Interferometer

of 16 /16
Measuring Polarizability with an Atom Interferometer Melissa Revelle

Embed Size (px)

description

Measuring Polarizability with an Atom Interferometer. Melissa Revelle. Overview. The Importance of Atomic Polarizability Our Interferometer Modeling the Experiment Progress Future. Why Atomic Polarizability?. Relates to Van der Waals forces Black body shifts for atomic clocks - PowerPoint PPT Presentation

Transcript of Measuring Polarizability with an Atom Interferometer

Page 1: Measuring Polarizability with an Atom Interferometer

Measuring Polarizability with an Atom Interferometer

Melissa Revelle

Page 2: Measuring Polarizability with an Atom Interferometer

Overview

The Importance of Atomic Polarizability

Our Interferometer Modeling the

Experiment Progress Future

Page 3: Measuring Polarizability with an Atom Interferometer

Why Atomic Polarizability?

Relates to Van der Waals forces Black body shifts for

atomic clocks Depths of optical

dipole traps for atoms

Precision of αNa = 0.5% Precision of αK = 2%

Ep

E

p p

Page 4: Measuring Polarizability with an Atom Interferometer

Using Phase Shift to Find Polarizability

Atom beam Detector

1G

v2

2xE

2G 3G

Page 5: Measuring Polarizability with an Atom Interferometer

Using Phase Shift to Find Polarizability

Atom beam Detector

1G

v2

2xE

x

2G 3G

Page 6: Measuring Polarizability with an Atom Interferometer

Using Phase Shift to Find Polarizability

Atom beam Detector

1G

v2

2xE

x

2G 3G

Page 7: Measuring Polarizability with an Atom Interferometer

Original Data

Atom flux at each grating position is recorded Polarizability relates to this phase shift

Page 8: Measuring Polarizability with an Atom Interferometer

Phase Shifts in an Atom Interferometer

From the Schrödinger equation for an atom beam, we get:

The total phase shift becomes:

))((2

)(xUTm

xk

1

)(v2

21 dxxE

Page 9: Measuring Polarizability with an Atom Interferometer

The Electric Field Gradient Region

x

y

Atom beams

y

x

z

Page 10: Measuring Polarizability with an Atom Interferometer

The Electric Field Gradient Region

x

y

y

x

z

Page 11: Measuring Polarizability with an Atom Interferometer

Finding the Equipotential Surfaces and Charge Density For an ideal wire and

an image wire:

22

22

0 )(

)(ln

2 xyd

xydV

o

g

d

y0 R

y

x

z

Atom beams

Page 12: Measuring Polarizability with an Atom Interferometer

Creating the Model

Integrate along a path in the x direction to get the phase shift.

L=distance from 1G to gradient region

a=grating period

mam

Lhs 55

v

v))v(cos()v(

v))v(sin()v(arctan

dP

dP

Page 13: Measuring Polarizability with an Atom Interferometer

Fitting the Data

The model for the E-field and phase shift is used as a fit function

Distance from Cylinder [mm]

Ph

ase

Sh

ift

[rad

]

Data

Fit Function

Page 14: Measuring Polarizability with an Atom Interferometer

Summary

We can precisely measure polarizability using atom interferometry.

The electric field must be accurate.

Velocity distribution is important

Page 15: Measuring Polarizability with an Atom Interferometer

Current and Future Progress

Improve precision polarizability of sodium and potassium to better than 1%

Measure the polarizability tensor components of molecules.

1.08.23 Na4.00.43 K

Page 16: Measuring Polarizability with an Atom Interferometer

References

A.Salop, E. Pollack, and B. Bederson, Phys. Rev. 124, 1431 (1961)

L. de Broglie, Ann. Phys. (Paris) 3, 22 (1925)

R. Molof, H. Schwartz, T. Miller, and B. Bederson, Phys. Rev. A 10, 1131 (1974)