Undergraduates
Why does the space shuttle returning to Earth cause two separate sonic booms?
Available to Physics Illinois majors only.
For Senior Thesis Research Projects, there exist(s) a long list of possible research projects - involving measurements of acoustic properties of various musical instruments - wind/brass/stringed/percussion/etc. families, and other topics, such as electric guitar and bass pickups, loudspeakers, room acoustics, as well as many other acoustical physics topics. Check out past POM-related undergraduate research projects, posted on the UIUC P498POM website: http://online.physics.uiuc.edu/courses/phys498pom/
Simulations of sheared materials, such as crystals, will be used to study the statistics of slip avalanches and failure of materials. The focus will be especially on universal properties that are expected to be common to many different materials, regardless of their microscopic details. The results will be compared to experimental data and observational data on earthquakes. The study requires excellent knowledge of C and C++, good analytical math skills, and the ability to write data analysis programs. In the course of this project the student will learn much about the theory of phase transitions and modern tools to study non-equilibrium systems with disorder.
Development of processes for growing thin films of high temperature cuprates and other exotic superconductor materials used pulsed laser ablation. Project involves growth of films and testing of their electronic properties. These films will be used in a variety of experiments to study superconductor materials and superconductor devices.
As part of the research and development for an experiment to measure the neutron electric dipole moment, we are investigating mechanisms to limit heat transfer through superfluid helium. A non-zero neutron electric dipole moment is a signal for physics beyond the standard model. In the experiment, we use superfluid helium for a variety of purposes including stopping the neutrons and acting as a scintillation detector for charged particles. In order to take advantage of so-called 'heat flush' purification in superfluid helium, we need to be able to control the amount of heat that flows in the superfluid. The project will involve a combination of calculations and measurements.
Many animals, e.g., migratory birds, can distinguish between North and South through detecting the geomagnetic field with their eyes. The physical mechanism involves the entanglement of electron spins that is altered through the field and affects a chemical reaction triggering a signaling process. In collaboration with experimental laboratories we seek to characterize the physical mechanism and neural processing underlying animal magnetoreception. The research combines protein physics, spin quantum physics, and neural physics. An earlier undergraduate project let to a much cited paper (Biophys J, 78:707-718, 2000) that started a new round of exciting investigations. For more information see: http://www.ks.uiuc.edu/Research/cryptochrome/
Graphene is a film made of just one monolayer of carbon atoms. It is pretty strong and has extremely unusual properties. For example the electronic excitations in such film are Dirac fermions. This means that they are somewhat analogous to relativistic electrons and positrons, which appear in Dirac quantum mechanics.
Our goal will be to find ways to produce and transport graphene layers using various types of micro-manipulators and lithographic techniques.
The underlying physics mechanism of the emission of a brief O(~ 100 psec) flash of light from a small bubble of air in water in a sinusoidal sound field - sonoluminescence - still eludes explanation today, many decades after its discovery. In collaboration with physicists at CERL (located in NW Champaign), we plan to measure the light emission spectrum from the visible region and into the far UV by doping the water with fluorescent quantum dots. The goal is to determine whether the sonoluminescence light emission curve follows that of a black-body spectrum, a bremsstrahlung spectrum, or something else. Since CERL is run by the US Army, applicants must be a US citizen, and must provide a resume, and also be interviewed by Dr. Charles Marsh, CERL PI for this project.
Our department's Center of the Physics of Living Cells investigates experimentally and theoretically the physical mechanisms underlying the swimming of bacteria. In this undergraduate project we have a very specific focus: bacteria swim with thin, flexible, long "hairs" coming out of bacterial cells. The "hairs" come out of the cell (at the base) with a 90 degree arc followed by a long straight segment; at the base the hairs are rotated by a motor. We want to develop a microscopic mechanical model of the "hairs' called flagella to understand how the rotation turns into a helical motion that hydrodynamically drives the bacterial cell forward. The development involves elasticity theory, elegant mathematics involving quaternions, and some computing. Another project in the group studies the flagellar structure and dynamics at the atomic level.
This project involves the development of a microcoil apparatus to measure nuclear magnetic resonance (NMR) on small single crystals. One student, Nate Burdick, has already completed an excellent senior thesis on this topic and we now need to carry on more experiments. You'll need to learn the basics of NMR and be willing to learn something about high frequency electronics. Ultimately we want to use this device to examine the magnetic behavior in a material known as a quantum spin liquid.
The Dark Energy Survey (DES) will map 1/4 of the southern sky to measure the properties of dark matter and dark energy. These mysterious entities comprise about 96% of the energy in the universe, but their properties are poorly known. We will study them by observing the galaxies, quasars, and supernovas that have existed over the past nine billion years (2/3 of the time since the big bang).
The DES involves the construction of a 500 megapixel digital camera for a 4-meter telescope in Chile. It also involves the development of improved data analysis techniques. Work on the data acquisition hardware and software and work on algorithm development for science analysis (for example, measuring cosmological parameters with supernovas) are both suitable projects.
Here are two web sites:
DES web site at Fermilab: https://www.darkenergysurvey.org/
The LSST web site (http://www.lsst.org/lsst) I also participate in LSST, a logger term, more ambitious project with similar science goals as DES.
Accreting black hole are the most powerful particle accelerators in the universe. This project involves (numerically) tracking charged particles in the fluctuating electromagnetic field surrounding a rotating black hole, and working to understand the physical processes that dominate particle acceleration.
Andreev reflection is a fascinating particle-conversion process in which an electron injected from a normal metal to a superconductor is retroflected as a hole. This process, worth studying itself, is also used as a powerful electronic spectroscopy of solids. We have built two point contact Andreev refection spectroscopy (PCARS) rigs for studying the electronic structure of novel superconductors. One is called the Cantilever Andreev Tunneling (CAT) rig which uses piezeoelectric elements, and the other uses a differential micromenter. With these rigs, we study the electronic structure of unconventional superconductors, including Fe-based and cuprate high-temperature superconductors, and heavy-fermions, to temperatures as low as 300 mK and applied magnetic fields up to 12 Tesla. In this measurement, a nanoscale tip of a normal metal (typically gold), a superconductor (Nb), or a ferromagnetic material, which has been electrochemically etched, is brought into contact with the superconducting sample. We have not only learned a great deal about the electronic spectroscopy of unconventional superconductors, including determining order-parameter symmetry, but we have also learned a great deal about the Andreev reflection process in novel materials. We will continue this work for electronic structure studies and to address long-standing questions of electronic transport between a metal and superconductor (Andreev reflection) with normal, superconducting, and ferromagnetic tips.
Undergraduate research projects include manufacturing gold nanoscale tips by electrochemical means, and developing and improving new types of tips. Students will be involved with the actual PCARS measurements, plus a variety of materials microanalysis techniques.
The project entails creating the tips using electrochemical techniques, polishing single-crystal superconductors with mechanical and chemical techniques, materials microanalysis to observe tip and surface quality, some film growth, and aiding in the cryogenic PCARS measurements. The student will gain an education in materials physics, cryogenic electronic transport, superconductivity and unconventional superconductivity.
Point contract spectroscopy (PCS) has been developed to measure the electronic structure of a variety of novel materials, including graphite, graphene, and topological insulators. In these experiments, the conductance measured between a nanoscale tip and sample surface reveals the density of electronic states. We study a variety of materials at temperatures down to 400 mK and applied magnetic fields up to 9 Tesla. We investigate electronic transport at interfaces using normal, superconducting, and ferromagnetic tips.
This project entails the manufacture the nanoscale tips using electrochemical techniques, polishing single-crystals with mechanical and chemical techniques, materials microanalysis to observe tip and surface quality, some film growth, and aiding in the cryogenic measurements. The student will gain an education in materials physics, cryogenic electronic transport, and novel, strongly-correlated electron materials.
When a superconductor is in good electrical contact with a normal metal, near the interface, the normal metal exhibits superconductivity and the superconducting properties of the superconductor are reduced. This is called the “superconducting proximity effect”. Fundamentally, this effect is not completely understood and addresses Cooper paring in novel materials. For applications, all commercial conventional superconducting transmission cables make use of this proximity effect, and this application has yet to be extended to high-temperature superconducting cables. In our laboratory, we study this effect using a semiconductor and semiconductor heterostructures as the normal metal because their electronic structure is tunable.
In previous work, we directly measured this proximity effect with a technique called “planar tunneling spectroscopy”, where a thin film of a superconductor is grown directly on the semiconductor and the conductance across the interface is measured. We found some interesting new effects, including more conduction than was predicted by theory.
We are continuing these measurements with in-situ superconductor-semiconductor, MBE-grown interfaces, where the superconductor is Nb and the semiconductor is an InAs-based heterostruicture.
The characterization will primarily consist of resistivity vs. temperature measurements, from room to cryogenic temperatures. These measurements are done in order to determine the quality of the films and the temperature of the onset of superconductivity as a function of Nb film thickness. Further measurements of the superconducting gap utilizing tunneling spectroscopy may also be conducted. Longer-range measurements address fundamental, yet unanswered, questions of the proximity effect.