Physics
Showing 201-300 of 392 Results
-
Raghu Mahajan
Visiting Assistant Professor
Current Research and Scholarly InterestsMy research interests are wide-ranging:
1) In the context of gravity, how does spacetime emerge from its dual quantum system? How does the dual quantum system encode the answers to questions that involve local physics in semi-classical gravity? How do you avoid the "firewall" paradox in the context of black-hole evaporation?
2) How do you calculate electrical and heat currents in strongly-coupled many-body systems? How do you explain the linear-in-temperature resistivity in high-temperature cuprates?
3) Use tensor network methods to study electrical and heat transport and also the real-time dynamics of systems out of thermal equilibrium. -
Dimitrios (Dimitris) Ntounis
Ph.D. Student in Physics, admitted Summer 2022
Ph.D. Minor, Computer ScienceCurrent Research and Scholarly InterestsExperimental Particle Physics, High Energy Physics, Future Colliders
-
Vahe Petrosian
Professor of Physics and of Applied Physics
BioHow do things evolve in the universe? How are particles accelerated in the universe?
Professor Petrosian’s research covers many topics in the broad area of theoretical astrophysics and cosmology, with a strong focus on high-energy astrophysical processes.
Cosmological studies deal with global properties of the universe, where the main focus is the understanding of the evolution of the universe at high redshifts, through studies of the evolutions of population of sources such as galaxies and quasars or active galactic nuclei, gamma-ray bursts, using new statistical techniques developed in collaboration with Prof. B. Efron of the Department of Statistics. Another area of research is the use of gravitational lensing in measuring mass in the universe.
High-energy astrophysics research involves interpretation of non-thermal astronomical sources where particles are accelerated to very high energies and emit various kinds of radiation. These processes occur on many scales and in all sorts of objects: in the magnetosphere of planets, in the interplanetary space, during solar and stellar flares, in the accretion disks and jets around stellar-size and super-massive black holes, at centers of galaxies, in gamma-ray bursts, in supernovae, and in the intra-cluster medium of clusters of galaxies. Plasma physics processes common in all these sources for acceleration of particles and their radiative signature is the main focus of the research here. -
Xiaoliang Qi
Professor of Physics
BioMy current research interest is the interplay of quantum entanglement, quantum gravity and quantum chaos. The characterization of quantum information and quantum entanglement has provided novel understanding to space-time geometry, and relate the dynamics of chaotic many-body systems to the dynamics of space-time, i.e. quantum gravity theory. Based on recent progress in holographic duality (also known as AdS/CFT), my goal is to use tools such as tensor networks and solvable models to provide more microscopic understanding to the emergent space-time geometry from quantum states and quantum dynamics.
I am also interested in topological states and topological phenomena in condensed matter systems.
You can find my recent research topics in some talks online:
http://online.kitp.ucsb.edu/online/chord18/opgrowth/
https://www.youtube.com/watch?v=__9VBaLfC6Y&t=42s
http://online.kitp.ucsb.edu/online/qinfo_c17/qi/ -
Stephen Quake
Lee Otterson Professor in the School of Engineering and Professor of Bioengineering, of Applied Physics and, by courtesy, of Physics
Current Research and Scholarly InterestsSingle molecule biophysics, precision force measurement, micro and nano fabrication with soft materials, integrated microfluidics and large scale biological automation.
-
Srinivas Raghu
Professor of Physics
On Leave from 10/01/2024 To 03/31/2025BioI am interested in the emergent behavior of quantum condensed matter systems. Some recent research topics include non-Fermi liquids, quantum criticality, statistical mechanics of strongly interacting and disordered quantum systems, physics of the half-filled Landau level, quantum Hall to insulator transitions, superconductor-metal-insulator transitions, and the phenomenology of quantum materials.
Past contributions that I'm particularly proud of include the co-founding of the subject of topological photonics (with Duncan Haldane), scaling theories of non-Fermi liquid metals (with Shamit Kachru and Gonzalo Torroba), Euclidean lattice descriptions of Chern-Simons matter theories and their dualities in 2+1 dimensions (with Jing-Yuan Chen and Jun Ho Son), and 'dual' perspectives of quantum Hall transitions (with Prashant Kumar and Michael Mulligan). -
Monika Schleier-Smith
Associate Professor of Physics
Current Research and Scholarly InterestsIn between the few-particle realm where we have mastered quantum mechanics and the macroscopic domain describable by classical physics, there lies a broad swath of territory where quantum effects are relevant but still largely out of our control and partly beyond our comprehension. This territory includes metrological instruments whose precision is limited by the quantum projection noise of millions of atoms; and materials whose bulk properties emerge from many-body interactions intractable to simulation on classical computers. Professor Schleier-Smith’s research aims to advance our control and understanding of many-particle quantum systems by engineering new quantum states and Hamiltonians with ensembles of laser-cooled atoms.
-
H Schwettman
Professor of Physics, Emeritus
BioAlan received his PhD from Rice University. He has acted as a research associate, associate professor, and professor at Stanford University. Research interests include the development of optical techniques that exploit the unique capabilities of the Free Electron Laser (FEL) in materials and biomedical research.
-
Zhi-Xun Shen
Paul Pigott Professor of Physical Sciences, Professor of Applied Physics and of Physics
On Partial Leave from 01/01/2025 To 06/30/2025Current Research and Scholarly InterestsDr. Shen's main research interest lies in the area of condensed matter and materials physics, as well as the applications of materials and devices. He develops photon based innovative instrumentation and advanced experimental techniques, ranging from angle-resolved photoemission to microwave imaging, soft x-ray scattering and time domain spectroscopy and scattering. He has created a body of literature that advanced our understanding of quantum materials, including superconductors, semiconductors, novel magnets, topological insulators, novel carbon and electron emitters. He is best known for his discoveries of the momentum structure of anisotropic d-wave pairing gap and anomalous normal state pseudogap in high temperature superconductors. He has further leveraged the advanced characterization tool to make better materials through thin film and interface engineering.
-
Stephen Shenker
Richard Herschel Weiland Professor
Current Research and Scholarly InterestsProfessor Shenker’s research focuses on quantum gravity, in particular string theory and M theory, with an emphasis on nonperturbative aspects.
-
Eva Silverstein
Wells Family Director of the Stanford Institute for Theoretical Physics and Professor of Physics
BioProfessor Silverstein conducts research in theoretical physics -- particularly gravitation and cosmology, as well as recently developing new methods and applications for machine learning.
What are the basic degrees of freedom and interactions underlying gravitational and particle physics? What is the mechanism behind the initial seeds of structure in the universe, and how can we test it using cosmological observations? Is there a holographic framework for cosmology that applies throughout the history of the universe, accounting for the emergent effects of horizons and singularities? What new phenomena arise in quantum field theory in generic conditions such as finite density, temperature, or in time dependent backgrounds?
Professor Silverstein attacks basic problems in several areas of theoretical physics. She develops concrete and testable mechanisms for cosmic inflation, accounting for its sensitivity to very high energy physics. This has led to a fruitful interface with cosmic microwave background research, contributing to a more systematic analysis of its observable phenomenology.
Professor Silverstein also develops mechanisms for stabilizing the extra dimensions of string theory to model the accelerated expansion of the universe. In addition, Professor Silverstein develops methods to address questions of quantum gravity, such as singularity resolution and the physics of black hole and cosmological horizons.
Areas of focus:
- optimization algorithms derived from physical dynamics, analyzing its behavior and advantages theoretically and in numerical experiments
- UV complete mechanisms and systematics of cosmic inflation, including string-theoretic versions of large-field inflation (with gravity wave CMB signatures) and novel mechanisms involving inflaton interactions (with non-Gaussian signatures in the CMB)
-Systematic theory and analysis of primordial Non-Gaussianity, taking into account strongly non-linear effects in quantum field theory encoded in multi-point correlation functions
-Long-range interactions in string theory and implications for black hole physics
- Concrete holographic models of de Sitter expansion in string theory, aimed at upgrading the AdS/CFT correspondence to cosmology
- Mechanisms for non-Fermi liquid transport and $2k_F$ singularities from strongly coupled finite density quantum field theory
- Mechanisms by which the extra degrees of freedom in string theory induce transitions and duality symmetries between spaces of different topology and dimensionality -
Jon Simon
Joan Reinhart Professor and Professor of Applied Physics
Current Research and Scholarly InterestsJon's group focuses on exploring synthetic quantum matter using the unique tools available through quantum and classical optics. We typically think of photons as non-interacting, wave-like particles. By harnessing recent innovations in Rydberg-cavity- and circuit- quantum electrodynamics, the Simonlab is able to make photons interact strongly with one another, mimicking collisions between charged electrons. By confining these photons in ultra-low-loss metamaterial structures, the teams "teach" the photons to behave as though they have mass, are in traps, and are experiencing magnetic fields, all by using the structures to tailor the optical dispersion. In total, this provides a unique platform to explore everything from Weyl-semi-metals, to fractional quantum hall puddles, to Mott insulators and quantum dots, all made of light.
The new tools developed in this endeavor, from twisted fabry-perot resonators, to Rydberg atom ensembles, Floquet-modulated atoms, and coupled cavity optical mode converters, have broad applications in information processing and communication. Indeed, we are now commissioning a new experiment aimed at interconverting optical and mm-wave photons using Rydberg atoms inside of crossed optical and superconducting millimeter resonators as the transducer. -
Todd Smith
Professor (Research) of Physics, Emeritus
BioTodd received his PhD from Rice University. He acted as an assistant professor of physics and electrical engineering, senior research physicist, and professor of physics. Research interests include experimental accelerator physics, laser physics, and superconductivity. His specialty is free electron lasers.
