Research Groups with Current Faculty
With so many recent, fundamental discoveries (e.g., dark energy, dark matter, black holes, extrasolar planets), our understanding of the size and future of the universe is changing, making this the golden era of astronomy/ astrophysics research.
Astrophysical environments offer unique opportunities to study the behavior of matter under extreme conditions that are often impossible to attain in Earth-based laboratories. To understand the objects and events in the cosmos, astrophysicists combine knowledge from diverse areas of physics, mathematics, statistics, and image processing. Research students in Astrophysics thus obtain a broad and well-rounded education.
The astrophysics group at USC is engaged in research in extragalactic astrophysics
and observational cosmology. Our work focuses on quasars, distant galaxies, intergalactic
matter, and the evolution of these objects with cosmic time.
Some of the key scientific questions we are trying to address are: how did the cosmic abundances of the chemical elements build up with time? How did the processes of star formation and gas consumption progress in galaxies? How did the structure and shapes of galaxies get established over billions of years?
Our research uses primarily optical, infrared, and ultraviolet facilities, and is funded by the NSF and NASA. We use a wide range of observing facilities in Chile, Hawaii, Arizona, and New Mexico, especially the Magellan Clay telescope, the Very Large Telescope (VLT), the Gemini telescopes, the Keck telescopes, and the Apache Point Observatory (APO), In addition, we use the Hubble Space Telescope and the Spitzer Space Telescope to access parts of the electromagnetic spectrum that are attenuated by the Earth's atmosphere. Our group has attracted several USC students, and includes close collaborators at a number of institutions worldwide.
The condensed matter group has varied activities in the interdisciplinary areas of condensed matter physics, material science, and nanotechnology. We have a group of eight condensed matter people in the department engaged in a wide variety of research projects, some of which is described below.
Yaroslaw Bazaliy is engaged in the theoretical study of the behavior of nanomagnets in the framework of the new research area called spintronics. Spintronics uses spin currents and spin density similar to the way in which the electric current and charge are used in ordinary electronics.
Mas Crawford’s group studies magnetism and magnetic materials, researching new approaches to measure the fundamental properties of magnetic materials, specifically at nanometer length scales and picosecond time scales.
Rick Creswick's research covers both the foundations of statistical physics and condensed matter physics. Currently he is investigating analogues of the famous "spin echo" in systems of charged particles. These systems exhibit a symmetry that allows their time evolution to be reversed, and therefore offers an interesting laboratory in which to study the thermodynamic arrow of time. In collaboration with the particle astrophysics group, he is studying the feasibility of using various materials for low temperature bolometers and the possibility that channeling by ions recoiling from collisions with WIMPs (weakly interacting massive particles) may help reveal the presence of dark matter.
Scott Crittenden’s group works on bacteria that generate electricity as a natural byproduct of metabolism with the purely biological nanowires they produce and on the development of new techniques for scanning probe microscopy to explore material properties at the atomic scale.
Timir Datta’s group projects involve high temperature superconductivity, mesoscopic quantum transport, deterministic chaos, and the effects of disorder in linear and non-linear systems, and experimental measurements of gravity.
Milind Kunchur’s group is involved in two main areas: (1) Phenomena in superconducting nanowires and nanostructured thin films at ultra-short time scales and under extreme conditions. (2) Psychophysics, auditory neurophysiology, and high-fidelity audio.
Yuriy Pershin works in the field of computational/theoretical physics. His current research concerns investigation of charge and spin transport in molecules, semiconductor structures and other submicron electronic devices. He is also interested in different aspects of transport in biological systems.
Yanwen Wu's group investigates the optical properties of nanomaterials. There are three main research directions that 1) characterize and control the coupling dynamics of a hybrid plasmonic/quantum dot system for applications in photonics and optical information processing, 2) study the interaction between the ferroelectric and ferrimagnetic components in multiferroic heterostructure nanowires using second harmonic generation, and 3) functionalize ferroelectric polymers as a dynamic platform to control and manipulate nanomaterials such as quantum dots and 2D materials.
We have built up a significant set of shared use equipment that is officially part of the Nanocenter although most of it is actually in physics faculty laboratories. For major equipment, we have multiple atomic force microscopes, a bacterial fermenter, a confocal microscope, two SEMs, one with 1 nm resolution, a femtosecond pulsed laser, multiple thermal, plasma, and e-gun evaporators, a reactive ion etcher, and multiple low temperature dilution refrigerators.
Interdisciplinary collaboration is common; we work with people in Chemistry, Mechanical Engineering, Electrical Engineering, the Medical School, and the History department.
The very fundamental particles found in nature are leptons (electrons and their charged cousins, and neutrinos) and quarks. The Standard Model (SM) describes how these interact via the strong and electroweak forces. Our group studies neutrinos which have puzzling behavior unexplained by the Standard Model; we also study the nature of the SM forces, with emphasis on searches for new phenomena that may lie beyond.
In particular, we focus on studies of particles that contain the bottom and charm
quarks; such decays may provide evidence of fundamentally new particles or sources
of CP symmetry violation. This and other fundamental research is conducted using data
collected by the Belle and Belle II experiments at KEK in Japan.
We also focus on further studies of neutrino physics.
The physics of hadrons and nuclei is based on the strong interaction. There are two experimentally verified perturbative quantum field theories that describe nuclear phenomena: perturbative Quantum Chromodynamics (pQCD) at small distances which is governed by gluon fields; and Chiral Perturbation Theory (ChPT) at larger distances which is governed by pion fields. However, the non-abelian nature of the strong interaction gives rise to a non-perturbative "confinement regime" at intermediate distances where more than 98% of the mass of normal matter is generated. A major goal of present day nuclear physics is to understand the connection of the two perturbative regimes and the transition from one to the other. The medium energy nuclear physics group at the University of South Carolina (USC) is devoted to find and carry out the most pressing experiments using electromagnetic probes that broaden our understanding of the nuclear force in the confinement regime. The group's activities are therefore concentrated on in-medium modifications of hadronic properties and baryon spectroscopy. The research program uses multi-GeV photon and electron beams at the Continuous Electron Beam Accelerator Facility (CEBAF) located at the Thomas Jefferson National Accelerator Laboratory (JLab).
Particle Astrophysics focuses on phenomena in astrophysics and cosmology associated with the properties of elementary particles ranging from neutrinos to Weakly Interacting Massive Particles (WIMPS), hypothesized as the Cold Dark Matter (CDM). The USC group was early in the field and made the first terrestrial CDM search. CDM is needed to explain the dynamics of galaxies and important features of cosmological models used to explain the evolution of the universe. The gravitational effects of CDM on the velocity distribution of stars in spiral galaxies, is well established. It was motivated by the discovery in 1933 by Fritz Zwicky that far more mass is needed to explain the dynamics of Globular Clusters than appears in stars and dust. In 1985, the USC group, inspired by the astrophysics group at Max Planck Institute in Munich, led the first terrestrial search for the CDM in the Homestake goldmine in Lead, South Dakota. The USC has also led several searches for elementary particles called axions emitted by the sun. Axions result in the theory by Roberto Peccei and Helen Quinn that explains why the strong interactions of quantum chromodynamics, do not violate charge-parity (C-P) symmetry. The USC group now concentrates on the MAJORANA, and CUORE Experiments which are searches for the exotic zero-neutrino nuclear double-beta decay (0νββ − decay) which is only possible if neutrinos have mass and are their own antiparticles (Majorana particles). (0νββ − decay also violates the law of lepton-number conservation. Neutrino oscillation experiments imply that neutrinos may well have enough mass to allow this decay to be measurable, but they can only measure mass differences. The measurement of the decay rate would determine the absolute masses of all three neutrino mass eigenstates.
Theoretical Particle Physics group (Altschul, Gudkov, Mazur, Monin, Petrov and Schindler) is involved with research in several areas of theoretical physics ranging from quantum aspects of gravity and cosmology, neutron physics and CP, P and T non-conservation in nuclear reactions to exotic physics from beyond the standard model such as breaking of Lorentz invariance.
Professor Altschul's research focuses on the possibility of exotic physics beyond the standard model of particle physics such as Lorentz symmetry breaking. He is working on astrophysical tests of relativity. This work concerns obtaining limits on Lorentz invariance violation (LIV) from synchrotron and inverse Compton sources, the limits on neutron LIV from pulsar timing.
Professor Gudkov is working on theoretical problems related to the experimental program in fundamental neutron physics at the SNS such as neutron beta-decay, parity and time reversal violation effects. This work is connected with the search for possible extensions of the standard model. His research subjects range from the applications of a neutron interferometric methods to subjects such as constraining non-Newtonian models of gravity at the nanometer scale, that has emerged as a result of phenomenological applications of string models, to scattering of ultra cold neutrons on nano-size bubbles, neutron beta decay in effective field theory and CP-violation effects in nuclear reactions.
Professor Mazur's research focuses on quantum aspects of gravity and cosmology. His work on quantum mechanics of black holes and black hole thermodynamics has led to the theory of gravastars. Gravastars are ultra-cold and superdense thermally stable (positive heat capacity) macroscopic quantum objects that are the final state of gravitational collapse of matter. One may think of them as quantum superfluid droplets. It is the superfluid nature of gravastars that offers the signature distinguishing them from classical black holes. The present observational methods are reaching the limits that will allow to test the gravastar scenario for the final state of gravitational collapse. Mazur and his collaborators have also discovered the connection between quantum field theories on de Sitter space and conformal field theories (CFT) on the boundary, that is the so-called dS/CFT correspondence. Some applications of the dS/CFT results are the extension of the Harrison, Zeldovich and Peebles-Yu scaling in two-point correlations of the primordial density fluctuations, and in the microwave background radiation, to the general case of three-point and higher correlations. His group has been at the forefront in addressing some the most fundamental questions in quantum mechanics. Topics for which the group has gained worldwide recognition include non-locality aspects such as the Aharonov-Bohm effect, geometric and topological aspects such as the Aharonov-Anandan phase, and new approaches to quantum measurement such as protective and weak measurements. These efforts have lead to directly testable new predictions and applications in diverse fields such as chemistry, condensed matter physics, elementary particle physics, astrophysics, and cosmology.
Professor Petrov's research interests include applications of effective field theories to analyses of electroweak interactions and QCD, studies of CP-violation, and heavy flavor physics. He has authored numerous research papers and two textbooks, “Effective Field Theories” (World Scientific, 2016) and “Indirect Searches for New Physics” (CRC Press, 2021). He also organized several research conferences. His research is continuously funded by the U.S. Department of Energy and the U.S. National Science Foundation.
Professor Schindler is working on problems in hadronic physics related to the strong and weak interactions. He has worked on theoretical methods to describe the properties of single protons and neutrons as well as the interaction between two and more nucleons. His current research focuses on fundamental symmetries in two- and few-nucleon systems. This work is related to ongoing experimental efforts at neutron facilities such as the Spallation Neutron Source at Oak Ridge National Laboratory.
One of the fundamental forces in nature is the strong interaction, which is responsible for (among other things) the existence of atomic nuclei. The particles that take part in the strong interaction are called hadrons. The main research theme of the Theoretical Nuclear Physics group is the study of hadrons and their aggregates such as nuclei and neutron stars. This line of study is of great interest in its own right, but its importance is further augmented by the following aspects:
It sheds light on the relation between the hadronic phenomena and the underlying fundamental
interaction among quarks, which are the basic building blocks of hadrons.
The understanding of many astrophysical phenomena depends on our knowledge of relevant nuclear reactions.
The experimental studies of the fundamental processes (e.g., neutrino oscillation experiments) require input from hadron and nuclear physics for their accurate interpretations.
Currently, a main thrust of our research is directed to the application of effective field theory (known as chiral perturbation theory) to nuclear systems with the view to giving accurate predictions to the cross sections for various hadronic, electromagnetic and weak-interaction processes, in particular for those which are relevant to astrophysics and/or neutrino oscillation experiments.
Research Groups with Emeritus Faculty