Transcript Slide 1
Mallory Traxler April 2013 Continuous atom laser Continuous, coherent stream of atoms Outcoupled from a BEC Applications Atom interferometry of atom lasers: Electromagnetic fields Gravitational fields Precision measurement gyroscopes Atom lithography 2/39 Guide α Experimental apparatus Experiments Rydberg atom guiding Design in guide α and manufacture of guide β Improvements from guide α’s design Outlook 3/39 α 4/39 α 5/39 6/39 Φpmot≈3x109 s-1 <vz,pmot>≈22 m/s 2D+ MOT Φmmot≈4.8x108 s-1 2.2 m/s to 2.9 m/s ( ) v cos 7/39 Detect atoms at the end Uses pulsed probe (23) and probe repumper (12) Optimize atoms in the guide 8/39 Three lasers for excitation Repumper to get back to bright state 5S1/25P3/2 480 nm to 59D Ionize Voltages on electrode, guard tube, MCP direct ions upward to MCP for detection 9/39 α 10/39 High n-principal quantum number Data here with n=59 Physically r~n2 Very susceptible to electric fields α~n7 Strong large interactions Other Rydberg atoms Blackbody radiation 11/39 Excitation to 59D Variable delay time, td MI or FI Camera gated over ionization duration 12/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 13/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 14/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 15/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 16/39 Penning ionization Remote field ionization Initial delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 17/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 18/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 19/39 Penning ionization Remote field ionization Initial Delayed Thermal ionization (Radiative decay) Microwave ionization Field ionization 20/39 Vary td from 5 μs to 5 ms τMI=700 μs τ59D5/2=150 μs 21/39 State-selective field ionization Different electric field needed for different states 59D peak broadens State mixing 22/39 Rydberg atoms excited from ground state atoms trapped in guide Observe Rydberg guiding over several milliseconds using microwave ionization and state selective field ionization Numerous phenomena from Rydberg atoms within the guide 23/39 β 24/39 β Improvements over guide α Zeeman slower No launching Magnetic injection Mechanical shutter 25/39 Standard 6-beam MOT Fed by Zeeman slower Factor of 6.6 brighter Expect closer to 10x 26/39 Most complicated part of the design 4 racetrack 2MOT coils 8 injection coils Built-in water cooling Magnetic compression Mechanical shutter 27/39 4 racetrack coils produce quadrupole magnetic field Holes Optical access Venting of internal parts Shutter 2 locks for stationary shutter 28/39 8 injection coils of varying diameters Fits inside 2MOT coil package Water cooling for all Tapered inside and out 29/39 Magnetic compression Mount for waveplate-mirror Stationary shutter 30/39 Hand-turned on lathe 2MOT coils on form Injection coils directly on mount Labeled with UHV compatible ceramic beads 31/39 High current power supply Split off 2-3 A for each coil Adiabatically inject atoms into the guide 32/39 21 equally spaced silicon surfaces Bring guided atomic flow closer to these surfaces Atoms not adsorbed onto surface rethermalize at lower temperature 33/39 β Fully constructed Preliminary tests well on the way Good transfer of atoms into the 2MOT Need Zeeman slower and 2MOT working simultaneously to optimize 34/39 35/39 Increase capture volume of Zeeman slower Reduce transverse velocity by factor of x, increase density by factor of x2 Most optics already in place 36/39 Potential barrier at the end of the guide Form BEC upstream Use coil to create potential Study BEC loading dynamics, number fluctuations Later use light shield barrier Tunnel atoms through to make first continuous atom laser 37/39 PI Andrew Cadotte Andrew Schwarzkopf David Anderson Kaitlin Moore Nithiwadee Thaicharoen Sarah Anderson Stephanie Miller Yun-Jhih Chen Erik Power Rachel Sapiro Spencer Olson Rahul Mhaskar Cornelius Hempel Recent Ph.D. Eric Paradis Graduate Students Former Grad Students (on this project) Prof. Georg Raithel Former Post Docs Current Undergraduate Matt Boguslawski Former Undergrads Varun Vaidya Steven Moses Karl Lundquist 38/39 39/39