Modern Experimental Physics Introduction for Physics 401 students

Spring 2014 Eugene V. Colla • Goals of the course • Experiments • Teamwork • Schedule and assignments • Your working mode

Physics 401 Spring 2013 2 • Primary: Learn how to “do” research  Each project is a mini-research effort

 How are experiments actually carried out

 Use of modern tools and modern analysis and data-recording techniques

 Learn how to document your work

• Secondary: Learn some modern physics

 Many experiments were once Nobel-prize-worthy efforts

 They touch on important themes in the development of modern physics

 Some will provide the insight to understand advanced courses

 Some are just too new to be discussed in textbooks

Physics 401 Spring 2013 3 Primary. Each project is a mini-research effort

Step1. Preparing: • Sample preparation • Wiring the setup • Testing electronics Preparing the samples for ferroelectric measurements

Courtesy of Emily Zarndt & Mike Skulski (F11)

Standing waves resonances in Second Step2. Taking data: Sound experiment If problems – go back to Courtesy of Mae Hwee Teo and Step 1. Vernie Redmon (F11)

Physics 401 Spring 2013 4 Primary. Each project is a mini-research effort

Plot of coincidence rate for 22Na against the angle between detectors A and B. The fit is a Step3. Data Analysis Gaussian function centred at If data is “bad” or not 179.30° with a full width at half maximum (FWHM) of 14.75°. enough data point – go back to Step 2 Courtesy of Bi Ran and Thomas Woodroof

Author#1 and Author#2 Step4. Writing report and preparing the talk

Physics 401 Spring 2013 5 Primary. How are experiments actually carried out ?

The procedures are The questions are not not all written out in the back of the chapter

The answers are not in the back of the book

You will have to learn to guide your own activities

Physics 401 Spring 2013 6 Primary. Use of modern tools and modern analysis and data-recording techniques

• Lock-in amplifiers • Digital scopes • Precise DMM’s • Multichannel analyzers • Cryogenic equipment • Temperature controllers • Sample preparation equipment • Microscopse • Modern optical equipment • etc.

Physics 401 Spring 2013 7 Primary. Learn how to document your work

On line. Electronic logbook

Making an analysis report, Writing formal report

Presenting your findings orally

Physics 401 Spring 2013 8 Secondary: Learn some modern physics

Many experiments were once 1913. Heike Kamerlingh Onnes Nobel-prize-worthy efforts "for his investigations on the properties of matter at 1986. Gerd Binnig low temperatures which led, "for their design of inter alia, to the production the scanning of liquid helium". tunneling microscope" 1973. Ivar Giaever "for their experimental discoveries "for their regarding tunneling phenomena in development of semiconductors and new methods for superconductors, respectively" nuclear magnetic precision measurements and discoveries in 1976. Pyotr Leonidovich connection Kapitsa therewith" "for his basic inventions and 1952. Felix Bloch and Edward Mills Purcell discoveries in the area of low-temperature physics"

Physics 401 Spring 2013 9 Secondary: Learn some modern physics

I. Giaver, Reviews of Modern Anna Miller and Everett Vacek, 2014 Physics, 46, 245, (1974) (unpublished)

2

Al-Al O -Pb 2 3 =1.34 meV T=1.55K

MM

/(dI/dV) 1

MS

)

dI/dV

(

0 0 4 8 12 16 ENERGY (IN UNITS OF ) Physics 401 Spring 2013 10 All experiments are divided in three main groups: Condensed Matter (CM), Nuclear/ Particle Physics (NP), Atomic/Molecular/Optics (AMO) • Condensed Matter (CM) – Superconductivity – Tunneling in superconductors Contactless detecting of the superconductivity. Penetration depth. – 2nd sound in He4 superfluid state – Ferroelectrics and ferroelectric phase transition. Dielectric and pyroelectric study (Ferro1) – Optical Investigation of the ferroelectric phase transition and domain formation (Ferro2) – Polarization of the ferroelectrics. Hysteresis loops (Ferro3) – Low temperature thermometry. Sensors calibration. – Pulsed NMR – Special Tools: • Vacuum film deposition • Atomic Force Microscope • Polarizing microscope

Physics 401 Spring 2013 11 • Nuclear / Particle (NP) – Alpha particle range in gasses – Cosmic ray muons: – Angular correlations in nuclear decay – Angular distribution of cosmic rays

• Atomic / Molecular / Optics (AMO) – Optical pumping of rubidium gas – Berry’s phase – Quantum erasure – Quantum Entanglement – Florescence spectroscopy

Physics 401 Spring 2013 12 Ferro1

(1)

Sample preparation

(2) Samples on the cryostat stage

100Hz 9 1K/min Results:

Temperature 6 (3) dependence of the

dielectric constant '/1000

 of barium titanate 3

0 150 200 250 300 350 400 450 500 setup T (K) Physics 401 Spring 2013 13 Ferro2

Setup

Domains in tetragonal phase of BaTO3

Idea of operating

PhysicsCourtesy 401 Spring of Dave 2013 Grych and Thomas 14 Hymel (F10) L

Second sound  Transmitter R 2 To lock-in

R1 Receiver Idea of the experiment T<2.17K

1.2

1.1 T = 1.57K 0.75

1.0 ) V

 0.50 (

0.9  R 0.8 0.25

0.7 )

0.6 40 50 60 70

V 

( 0.5 

R 0.4

0.3

0.2

0.1

0.0 0 100 200 300 400 500 600 700 800 900 ƒ (Hz) Final result Raw data

Physics 401 Spring 2013 15 Muon counting

Wiring Main stock of scintillators Courtesy of Deniz Köksal, Emily Zarndt

Muons precession in magnetic field

Physics 401 Spring 2013 16 Optical pumping

0.52

0.50

0.48

Energy transitions of Rb85 for 10.8 G. Intensity (a.u.) 0.46 85 Double quantum transitions can be seen Rb and occur when two photons are simultaneously absorbed. Courtesy of Natasha 0.44

Sachdeva (S2011) 5.14 5.16 5.18 5.20 5.22 5.24 5.26 5.28 f (MHz)

Physics 401 Spring 2013 17 • Many are just guides • A few purchased experiments have “real” manuals • We serve as your guides … like real research

An example of Lab manual

Physics 401 Spring 2013 18 Item Points Expt. documentation: elog reports, shift summaries, 180 Total plot quality; paper logbooks 60 / cycle Formal reports: physics case, quality of results, 600 Total depth of analysis, conclusions 100 / report Oral reports: motivation, organization of 225 presentation; fielding questions 75 / oral Total 1005 Effective point total will be 1000  grade

Physics 401 Spring 2013 19 Physics 401 Spring 2013 20 Physics 401 Spring 2013 21 • Total 20 – Fall and 6 - Summer seats

• The course is more appropriate for juniors and seniors

• Prerequisite: Credit or concurrent registration in PHYS 486.

• Instructor Approval Required

Physics 401 Spring 2013 22