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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
2
Physics 401 Spring 2013

3
• 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

4
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)
Step2. Taking data:
If problems – go back to
Step 1.
Standing waves
resonances in Second
Sound experiment
Courtesy of Mae Hwee Teo and
Vernie Redmon (F11)

5
Primary. Each project is a mini-research effort
Step3. Data Analysis
If data is “bad” or not
enough data point – go
back to Step 2
Step4. Writing report and
preparing the talk
Plot of coincidence rate for
22Na against the angle between
detectors A and B. The fit is a
Gaussian function centred at
179.30° with a full width at half
maximum (FWHM) of 14.75°.
Courtesy of Bi Ran and Thomas
Woodroof
Author#1 and
Author#2

Primary. How are experiments actually carried out ?
The procedures are
not all written out
The questions are not
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
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.
7

Primary. Learn how to document your work
On line. Electronic logbook
Making an analysis report,
Writing formal report
Presenting your findings
orally
8

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

I. Giaver, Reviews of Modern
Physics, 46, 245, (1974)
10
Secondary: Learn some modern physics
Anna Miller and Everett Vacek, 2014
(unpublished)
0 4 8 12 16
0
1
2
(
dI/dV
)
MS
/(dI/dV)
MM
ENERGY (IN UNITS OF )
Al-Al2
O3
-Pb
=1.34 meV
T=1.55K

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
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
12

Ferro1
Samples on the cryostat
stage
(1)
Sample preparation
setup
150 200 250 300 350 400 450 500
0
3
6
9
100Hz
T (K)

'/1000
1K/min
(2)
(3)
Results:
Temperature
dependence of the
dielectric constant
of barium titanate
13

Ferro2
Courtesy of Dave Grych and Thomas
Hymel (F10)
Setup
Domains in tetragonal phase of BaTO
Idea of operating
14

Transmitter
Receiver
To lock-in
L

R1
R2
T<2.17K
Idea of the experiment
0 100 200 300 400 500 600 700 800 900
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
40 50 60 70
0.25
0.50
0.75
T = 1.57K
ƒ (Hz)
R
(
V
)
R
(
V
)
Raw data
Final result
Second sound
15

Muon counting
Main stock of scintillators
Wiring
Courtesy of Deniz Köksal, Emily Zarndt
Muons precession in magnetic field
16

Optical pumping
5.14 5.16 5.18 5.20 5.22 5.24 5.26 5.28
0.44
0.46
0.48
0.50
0.52
Intensity
(a.u.)
f (MHz)
Energy transitions of Rb85 for 10.8 G.
Double quantum transitions can be seen
and occur when two photons are
simultaneously absorbed. Courtesy of Natasha
Sachdeva (S2011)
85Rb
17

18
An example of Lab manual
• Many are just
guides
• A few purchased
experiments have
“real” manuals
• We serve as your
guides … like real
research

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

• 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
22

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