Sankar Das Sarma
Encyclopedia
Sankar Das Sarma is an India
n-born American
theoretical
condensed matter
physicist
, who has worked in the areas of strongly correlated materials, graphene
, semiconductor physics, low-dimensional systems
, topological matter
, quantum Hall effect, nanoscience, spintronics
, collective properties of ultra-cold atomic and molecular systems
, optical lattice
, many-body theory
, and quantum computation.
http://www.faculty.umd.edu/FacAwards/duplist.html, a Fellow of the Joint Quantum Institute
(JQI), and the Director of the Condensed Matter Theory Center at the University of Maryland, College Park
, where he has been on the physics faculty since 1980. Das Sarma has co-authored http://www.umdphysics.umd.edu/images/CV/dassarma_cv.pdf more than 500 articles in the Physical Review
Journal series of the American Physical Society
, including more than 100 publications in Physical Review Letters, and with more than 24,000 citations to his publications, is one of the Institute for Scientific Information
Highly-Cited Researchers.
In collaboration with Chetan Nayak and Michael Freedman
of Microsoft Research
, Das Sarma introduced the nu=5/2 topological qubit http://prola.aps.org/abstract/PRL/v94/i16/e166802 in 2005, which has led to experiments in building a fault-tolerant quantum computer
based on two-dimensional semiconductor structures. In 2010 Das Sarma and his collaborators introduced the idea of generic topological quantum computation using localized Majorana fermion
in ordinary semiconductor materials. Das Sarma's work http://arxiv.org/abs/0705.1540 on graphene
has led to the theoretical understanding of graphene carrier transport properties at low densities where the inhomogeneous electron-hole puddles dominate the graphene landscape. Among Das Sarma's other well-known theoretical contributions http://www.umdphysics.umd.edu/images/CV/dassarma_cv.pdf to quantum condensed matter physics are: the self-consistent electronic structure calculation of semiconductor heterojunction-based high electron mobility transistor structures, electron-phonon interaction induced polaron
effects in low dimensional systems, collective excitation and quasiparticle
modes in semiconductor structures such as quantum wire
, quantum well
and superlattice
, hot electron relaxation in semiconductors, quantum Anderson localization
, many-body effects
and electron-electron interaction in semiconductors, canted antiferromagnetic states in quantum Hall effect, various spin transistor
systems, magnetic polaron theory of diluted magnetic semiconductor
, coupled spin qubit
s in semiconductor quantum dot
s, theory of quantum decoherence
of localized electron spins in solids, central spin decoherence problem, spectral diffusion of electron spins in solids, dynamical decoupling and quantum control, quantum transport theory in low dimensional semiconductor
s, bilayer quantum Hall systems, and realistic solid state effects in the fractional quantum Hall effect
phenomena. Das Sarma also made important contributions to the classical statistical mechanics
problem of dynamical growth of systems far from equilibrium where his work introduced the standard model for understanding the molecular beam epitaxy
of thin film
growth, both from a continuum field theory viewpoint http://prl.aps.org/abstract/PRL/v66/i18/p2348_1 in terms of the so-called Villain-Lai-Das Sarma equation and from the discrete atomistic viewpoint http://prl.aps.org/abstract/PRL/v66/i3/p325_1 in terms of the so-called Das Sarma-Tamborenea model.
Das Sarma came to the USA as a physics graduate student in 1974 after finishing his secondary school and undergraduate education in Kolkata, India where he was born. He received his PhD
in physics from Brown University
in 1979. Das Sarma has mentored a large number of PhD students and postdoctoral research associates at Maryland, having supervised 25 PhD students and 80 postdoctoral fellows in the 1982-2011 period, with about 50 of these advisees themselves working as theoretical physicists and physics professors all over the world.http://www.physics.umd.edu/cmtc/formermembers.html Das Sarma's research collaborators, as reflected in the coauthors of his scholarly publications, exceed 200 and span five continents. Although Das Sarma has spent his entire academic life as a faculty member at Maryland, he has been a visiting professor at many institutions during his professional career including Technical University of Munich
, IBM Thomas J. Watson Research Center
, University of Hamburg
, Cambridge University, University of California, Santa Barbara
, University of New South Wales
, Sandia National Laboratories
, University of Melbourne
, Kavli Institute for Theoretical Physics
in Santa Barbara, and Microsoft Station Q Research Centerhttp://stationq.ucsb.edu/. He is the editor of the book Perspectives in Quantum Hall Effects (ISBN 0-471-11216-X) and a co-author of several well-known review articles on many topics including spintronics, graphene, and quantum computation.
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
n-born American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
theoretical
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
condensed matter
Condensed matter physics
Condensed matter physics deals with the physical properties of condensed phases of matter. These properties appear when a number of atoms at the supramolecular and macromolecular scale interact strongly and adhere to each other or are otherwise highly concentrated in a system. The most familiar...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, who has worked in the areas of strongly correlated materials, graphene
Graphene
Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...
, semiconductor physics, low-dimensional systems
2DEG
A two-dimensional electron gas is a gas of electrons free to move in two dimensions, but tightly confined in the third. This tight confinement leads to quantized energy levels for motion in that direction, which can then be ignored for most problems. Thus the electrons appear to be a 2D sheet...
, topological matter
Topological order
In physics, topological order is a new kind of order in a quantum state that is beyond the Landau symmetry-breaking description. It cannot be described by local order parameters and long range correlations...
, quantum Hall effect, nanoscience, spintronics
Spintronics
Spintronics , also known as magnetoelectronics, is an emerging technology that exploits both the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-state devices.An additional effect occurs when a spin-polarized current is...
, collective properties of ultra-cold atomic and molecular systems
Ultracold atom
Ultracold atoms is a term used to describe atoms that are maintained at temperatures close to 0 kelvins , typically below some tenths of microkelvins , where their quantum-mechanical properties become important...
, optical lattice
Optical lattice
An optical lattice is formed by the interference of counter-propagating laser beams, creating a spatially periodic polarization pattern. The resulting periodic potential may trap neutral atoms via the Stark shift. Atoms are cooled and congregate in the locations of potential minima...
, many-body theory
Many-body theory
The many-body theory is an area of physics which provides the framework for understanding the collective behavior of vast assemblies of interacting particles. In general terms, the many-body theory deals with effects that manifest themselves only in systems containing large numbers of constituents...
, and quantum computation.
Career
Das Sarma is the Richard E. Prange Chair in Physics http://umdphysics.umd.edu/index.php/about-us/people/faculty/125-dassarm.html, a Distinguished University ProfessorProfessor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
http://www.faculty.umd.edu/FacAwards/duplist.html, a Fellow of the Joint Quantum Institute
Joint Quantum Institute
The Joint Quantum Institute is a publicly funded research organization dedicated to basic and applied research in quantum physics, with particular emphasis on quantum information science.- Location :...
(JQI), and the Director of the Condensed Matter Theory Center at the University of Maryland, College Park
University of Maryland, College Park
The University of Maryland, College Park is a top-ranked public research university located in the city of College Park in Prince George's County, Maryland, just outside Washington, D.C...
, where he has been on the physics faculty since 1980. Das Sarma has co-authored http://www.umdphysics.umd.edu/images/CV/dassarma_cv.pdf more than 500 articles in the Physical Review
Physical Review
Physical Review is an American scientific journal founded in 1893 by Edward Nichols. It publishes original research and scientific and literature reviews on all aspects of physics. It is published by the American Physical Society. The journal is in its third series, and is split in several...
Journal series of the American Physical Society
American Physical Society
The American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...
, including more than 100 publications in Physical Review Letters, and with more than 24,000 citations to his publications, is one of the Institute for Scientific Information
Institute for Scientific Information
The Institute for Scientific Information was founded by Eugene Garfield in 1960. It was acquired by Thomson Scientific & Healthcare in 1992, became known as Thomson ISI and now is part of the Healthcare & Science business of the multi-billion dollar Thomson Reuters Corporation.ISI offered...
Highly-Cited Researchers.
In collaboration with Chetan Nayak and Michael Freedman
Michael Freedman
Michael Hartley Freedman is a mathematician at Microsoft Station Q, a research group at the University of California, Santa Barbara. In 1986, he was awarded a Fields Medal for his work on the Poincaré conjecture. Freedman and Robion Kirby showed that an exotic R4 manifold exists.Freedman was born...
of Microsoft Research
Microsoft Research
Microsoft Research is the research division of Microsoft created in 1991 for developing various computer science ideas and integrating them into Microsoft products. It currently employs Turing Award winners C.A.R. Hoare, Butler Lampson, and Charles P...
, Das Sarma introduced the nu=5/2 topological qubit http://prola.aps.org/abstract/PRL/v94/i16/e166802 in 2005, which has led to experiments in building a fault-tolerant quantum computer
Topological quantum computer
A topological quantum computer is a theoretical quantum computer that employs two-dimensional quasiparticles called anyons, whose world lines cross over one another to form braids in a three-dimensional spacetime . These braids form the logic gates that make up the computer...
based on two-dimensional semiconductor structures. In 2010 Das Sarma and his collaborators introduced the idea of generic topological quantum computation using localized Majorana fermion
Majorana fermion
In physics, a Majorana fermion is a fermion which is its own anti-particle. The term is used in opposition to Dirac fermion, which describes particles that differ from their antiparticles...
in ordinary semiconductor materials. Das Sarma's work http://arxiv.org/abs/0705.1540 on graphene
Graphene
Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...
has led to the theoretical understanding of graphene carrier transport properties at low densities where the inhomogeneous electron-hole puddles dominate the graphene landscape. Among Das Sarma's other well-known theoretical contributions http://www.umdphysics.umd.edu/images/CV/dassarma_cv.pdf to quantum condensed matter physics are: the self-consistent electronic structure calculation of semiconductor heterojunction-based high electron mobility transistor structures, electron-phonon interaction induced polaron
Polaron
A polaron is a quasiparticle composed of a charge and its accompanying polarization field. A slow moving electron in a dielectric crystal, interacting with lattice ions through long-range forces will permanently be surrounded by a region of lattice polarization and deformation caused by the moving...
effects in low dimensional systems, collective excitation and quasiparticle
Quasiparticle
In physics, quasiparticles are emergent phenomena that occur when a microscopically complicated system such as a solid behaves as if it contained different weakly interacting particles in free space...
modes in semiconductor structures such as quantum wire
Quantum wire
In condensed matter physics, a quantum wire is an electrically conducting wire, in which quantum effects are affecting transport properties. Due to the quantum confinement of conduction electrons in the transverse direction of the wire, their transverse energy is quantized into a series of...
, quantum well
Quantum well
A quantum well is a potential well with only discrete energy values.One technology to create quantization is to confine particles, which were originally free to move in three dimensions, to two dimensions, forcing them to occupy a planar region...
and superlattice
Superlattice
Superlattice is a periodic structure of layers of two materials. Typically, the thickness of one layer is several nanometers.- Discovery :Superlattices were discovered early in the 20th century through their special X-ray diffraction patterns....
, hot electron relaxation in semiconductors, quantum Anderson localization
Anderson localization
In condensed matter physics, Anderson localization, also known as strong localization, is the absence of diffusion of waves in a disordered medium. This phenomenon is named after the American physicist P. W...
, many-body effects
Many-body problem
The many-body problem is a general name for a vast category of physical problems pertaining to the properties of microscopic systems made of a large number of interacting particles. Microscopic here implies that quantum mechanics has to be used to provide an accurate description of the system...
and electron-electron interaction in semiconductors, canted antiferromagnetic states in quantum Hall effect, various spin transistor
Spin transistor
The magnetically-sensitive transistor , originally proposed in 1990 and currently still being developed, is an improved design on the common transistor invented in the 1940s...
systems, magnetic polaron theory of diluted magnetic semiconductor
Magnetic semiconductor
Magnetic semiconductors are semiconductor materials that exhibit both ferromagnetism and useful semiconductor properties. If implemented in devices, these materials could provide a new type of control of conduction...
, coupled spin qubit
Qubit
In quantum computing, a qubit or quantum bit is a unit of quantum information—the quantum analogue of the classical bit—with additional dimensions associated to the quantum properties of a physical atom....
s in semiconductor quantum dot
Quantum dot
A quantum dot is a portion of matter whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules. They were discovered at the beginning of the 1980s by Alexei...
s, theory of quantum decoherence
Quantum decoherence
In quantum mechanics, quantum decoherence is the loss of coherence or ordering of the phase angles between the components of a system in a quantum superposition. A consequence of this dephasing leads to classical or probabilistically additive behavior...
of localized electron spins in solids, central spin decoherence problem, spectral diffusion of electron spins in solids, dynamical decoupling and quantum control, quantum transport theory in low dimensional semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
s, bilayer quantum Hall systems, and realistic solid state effects in the fractional quantum Hall effect
Fractional quantum Hall effect
The fractional quantum Hall effect is a physical phenomenon in which the Hall conductance of 2D electrons shows precisely quantised plateaus at fractional values of e^2/h. It is a property of a collective state in which electrons bind magnetic flux lines to make new quasiparticles, and excitations...
phenomena. Das Sarma also made important contributions to the classical statistical mechanics
Statistical mechanics
Statistical mechanics or statistical thermodynamicsThe terms statistical mechanics and statistical thermodynamics are used interchangeably...
problem of dynamical growth of systems far from equilibrium where his work introduced the standard model for understanding the molecular beam epitaxy
Molecular beam epitaxy
Molecular beam epitaxy is one of several methods of depositing single crystals. It was invented in the late 1960s at Bell Telephone Laboratories by J. R. Arthur and Alfred Y. Cho.-Method:...
of thin film
Thin film
A thin film is a layer of material ranging from fractions of a nanometer to several micrometers in thickness. Electronic semiconductor devices and optical coatings are the main applications benefiting from thin film construction....
growth, both from a continuum field theory viewpoint http://prl.aps.org/abstract/PRL/v66/i18/p2348_1 in terms of the so-called Villain-Lai-Das Sarma equation and from the discrete atomistic viewpoint http://prl.aps.org/abstract/PRL/v66/i3/p325_1 in terms of the so-called Das Sarma-Tamborenea model.
Das Sarma came to the USA as a physics graduate student in 1974 after finishing his secondary school and undergraduate education in Kolkata, India where he was born. He received his PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
in physics from Brown University
Brown University
Brown University is a private, Ivy League university located in Providence, Rhode Island, United States. Founded in 1764 prior to American independence from the British Empire as the College in the English Colony of Rhode Island and Providence Plantations early in the reign of King George III ,...
in 1979. Das Sarma has mentored a large number of PhD students and postdoctoral research associates at Maryland, having supervised 25 PhD students and 80 postdoctoral fellows in the 1982-2011 period, with about 50 of these advisees themselves working as theoretical physicists and physics professors all over the world.http://www.physics.umd.edu/cmtc/formermembers.html Das Sarma's research collaborators, as reflected in the coauthors of his scholarly publications, exceed 200 and span five continents. Although Das Sarma has spent his entire academic life as a faculty member at Maryland, he has been a visiting professor at many institutions during his professional career including Technical University of Munich
Technical University of Munich
The Technische Universität München is a research university with campuses in Munich, Garching, and Weihenstephan...
, IBM Thomas J. Watson Research Center
Thomas J. Watson Research Center
The Thomas J. Watson Research Center is the headquarters for the IBM Research Division.The center is on three sites, with the main laboratory in Yorktown Heights, New York, 38 miles north of New York City, a building in Hawthorne, New York, and offices in Cambridge, Massachusetts.- Overview :The...
, University of Hamburg
University of Hamburg
The University of Hamburg is a university in Hamburg, Germany. It was founded on 28 March 1919 by Wilhelm Stern and others. It grew out of the previous Allgemeines Vorlesungswesen and the Kolonialinstitut as well as the Akademisches Gymnasium. There are around 38,000 students as of the start of...
, Cambridge University, University of California, Santa Barbara
University of California, Santa Barbara
The University of California, Santa Barbara, commonly known as UCSB or UC Santa Barbara, is a public research university and one of the 10 general campuses of the University of California system. The main campus is located on a site in Goleta, California, from Santa Barbara and northwest of Los...
, University of New South Wales
University of New South Wales
The University of New South Wales , is a research-focused university based in Kensington, a suburb in Sydney, New South Wales, Australia...
, Sandia National Laboratories
Sandia National Laboratories
The Sandia National Laboratories, managed and operated by the Sandia Corporation , are two major United States Department of Energy research and development national laboratories....
, University of Melbourne
University of Melbourne
The University of Melbourne is a public university located in Melbourne, Victoria. Founded in 1853, it is the second oldest university in Australia and the oldest in Victoria...
, Kavli Institute for Theoretical Physics
Kavli Institute for Theoretical Physics
The Kavli Institute for Theoretical Physics is a research institute of the University of California, Santa Barbara. KITP is one of the most renowned institutes for theoretical physics in the world. KITP programs bring theorists in physics and related fields together to work together on topics at...
in Santa Barbara, and Microsoft Station Q Research Centerhttp://stationq.ucsb.edu/. He is the editor of the book Perspectives in Quantum Hall Effects (ISBN 0-471-11216-X) and a co-author of several well-known review articles on many topics including spintronics, graphene, and quantum computation.