Mark George Raizen is an American physicist who conducts experiments on quantum optics and atom optics.
Mark George Raizen is an American physicist who conducts experiments on quantum optics and atom optics.
Raizen was born in New York City. Raizen's uncle, Dr. Robert F. Goldberger, was provost of Columbia University and deputy director for science at the NIH.
Raizen attended The Walden School on the Upper West Side, until his family moved to Israel. He graduated from De Shalit High School and received his undergraduate degree in mathematics from Tel Aviv University in 1980. He continued his graduate education at the University of Texas at Austin, under the guidance of Steven Weinberg (Nobel Prize in Physics, 1979) and Jeff Kimble (California Institute of Technology).
Raizen completed his Ph.D. in 1989. From 1989 to 1991, Raizen was a National Research Council (NRC) post-doc at the Time and Frequency Division of the National Institute of Standards and Technology, working with David Wineland, (Nobel Prize in Physics, 2012).
In 1991, Raizen returned to Austin and The University of Texas where he became an assistant professor of physics. He was promoted to associate professor in 1996 and full professor in 2000. Raizen holds the Sid W. Richardson Foundation Regents Chair in physics. In September, 2017, Raizen assumed a joint appointment as a professor in the Department of Pediatrics at the Dell Medical School.
Raizen started his scientific career in theoretical particle physics in 1984 with Steven Weinberg. In 1985, Raizen moved into experimental physics where he began his work with Jeff Kimble. In his graduate work, Raizen was instrumental in one of the first experiments that measured Squeezed states of light and also observed the Vacuum Rabi splitting in the optical domain.
While at NIST, Raizen developed a miniature linear ion trap which has become the basis for quantum information with trapped ions.
At the University of Texas, Austin, the research program in the Raizen Group uses laser cooling and trapping of neutral atoms to study fundamental problems. They observed dynamical localization in the momentum of atoms, the quantum suppression of chaos.
In other experiments, Raizen and his group investigated quantum transport of atoms in an accelerating optical lattice. They studied the loss mechanism during the acceleration due to quantum tunneling. For short times, they found a deviation from the exponential decay law in the survival probability. This short-time deviation from exponential decay was then used to suppress or enhance the decay rate, effects known as the Quantum Zeno effect or Anti-Zeno effect.
Raizen and his group built two experiments with Bose-Einstein Condensate in rubidium and sodium. They developed a system for the study and control of quantum statistics of atoms and quantum entanglement. The system includes a condensate in an optical box trap together with single atom detection.
In a separate experiment, they demonstrated coherent slowing of supersonic beams. Using an atomic paddle, a slow monochromatic beam of ground state helium was produced. In a different approach, pulsed magnetic fields were used to stop paramagnetic atoms and molecules. To further cool these particles, Raizen and his collaborators introduced the concept of a one-way barrier, or one-way wall, which is used to accumulate atoms or molecules in optical tweezers. This method was realized experimentally by the Raizen Group in December, 2007. This cooling method is a physical realization of informational cooling, originally proposed by Leó Szilárd in 1929. This proposal used the concept of information entropy to resolve the paradox of Maxwell's Demon. Together, these methods enable the trapping and cooling of atoms that span most of the periodic table and paramagnetic molecules.
In 2009, Raizen and his group built an experiment to study Brownian motion of a bead of glass held in optical tweezers in air. In 1907, Albert Einstein published a paper in which he considered the instantaneous velocity of Brownian motion, and showed that it could be used to test the Equipartition Theorem, one of the basic tenets of statistical mechanics. In this paper, Einstein concluded that the instantaneous velocity would be impossible to measure in practice due to the very rapid randomization of the motion. In the spring of 2010, the Raizen Group measured the instantaneous velocity of a Brownian particle in air. In 2014, they completed the same measurement in water and acetone. The velocity data was used to verify the Maxwell-Boltzmann velocity distribution, and the equipartition theorem for a Brownian particle.
These methods of controlling atoms were used by Raizen and collaborators to separate isotopes with high efficiency. The experiment demonstrated enrichment of lithium-7 to a purity over 99.95% in a single pass. The separation method is termed magnetically activated and guided isotope separation (MAGIS). One application of the work will be to produce enriched isotopes for medicine at a non-profit entity, The Pointsman Foundation, where Raizen serves as chairman of the board.
Raizen is married and resides in Austin and San Antonio, Texas. He is an advocate for historical preservation and animal rights.
Raizen is also a fellow of American Physical Society and the Optical Society of America.
Brownian motion is the random motion of particles suspended in a medium.
In condensed matter physics, a Bose–Einstein condensate (BEC) is a state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero. Under such conditions, a large fraction of bosons occupy the lowest quantum state, at which microscopic quantum mechanical phenomena, particularly wavefunction interference, become apparent macroscopically. More generally, condensation refers to the appearance of macroscopic occupation of one or several states: for example, in BCS theory, a superconductor is a condensate of Cooper pairs. As such, condensation can be associated with phase transition, and the macroscopic occupation of the state is the order parameter.
Laser cooling includes a number of techniques where atoms, molecules, and small mechanical systems are cooled with laser light. The directed energy of lasers is often associated with heating materials, e.g. laser cutting, so it can be counterintuitive that laser cooling often results in sample temperatures approaching absolute zero. Laser cooling relies on the change in momentum when an object, such as an atom, absorbs and re-emits a photon. For an ensemble of particles, their thermodynamic temperature is proportional to the variance in their velocity. That is, more homogeneous velocities among particles corresponds to a lower temperature. Laser cooling techniques combine atomic spectroscopy with the aforementioned mechanical effect of light to compress the velocity distribution of an ensemble of particles, thereby cooling the particles.
Matter waves are a central part of the theory of quantum mechanics, being half of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave.
Optical tweezers are scientific instruments that use a highly focused laser beam to hold and move microscopic and sub-microscopic objects like atoms, nanoparticles and droplets, in a manner similar to tweezers. If the object is held in air or vacuum without additional support, it can be called optical levitation.
The quantum Zeno effect is a feature of quantum-mechanical systems allowing a particle's time evolution to be slowed down by measuring it frequently enough with respect to some chosen measurement setting.
Quantum optics is a branch of atomic, molecular, and optical physics dealing with how individual quanta of light, known as photons, interact with atoms and molecules. It includes the study of the particle-like properties of photons. Photons have been used to test many of the counter-intuitive predictions of quantum mechanics, such as entanglement and teleportation, and are a useful resource for quantum information processing.
The annus mirabilis papers are the four papers that Albert Einstein published in Annalen der Physik, a scientific journal, in 1905. These four papers were major contributions to the foundation of modern physics. They revolutionized science's understanding of the fundamental concepts of space, time, mass, and energy. Because Einstein published these remarkable papers in a single year, 1905 is called his annus mirabilis.
Arthur Ashkin was an American scientist and Nobel laureate who worked at Bell Laboratories and Lucent Technologies. Ashkin has been considered by many as the father of optical tweezers, for which he was awarded the Nobel Prize in Physics 2018 at age 96, becoming the oldest Nobel laureate until 2019 when John B. Goodenough was awarded at 97. He resided in Rumson, New Jersey.
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 at the potential extrema. The resulting arrangement of trapped atoms resembles a crystal lattice and can be used for quantum simulation.
The Institut d'optique Graduate School, nicknamed SupOptique or IOGS, is a graduate school of Paris-Saclay University and ParisTech.
In condensed matter physics, an ultracold atom is an atom with a temperature near absolute zero. At such temperatures, an atom's quantum-mechanical properties become important.
The timeline of quantum mechanics is a list of key events in the history of quantum mechanics, quantum field theories and quantum chemistry.
This glossary of physics is a list of definitions of terms and concepts relevant to physics, its sub-disciplines, and related fields, including mechanics, materials science, nuclear physics, particle physics, and thermodynamics. For more inclusive glossaries concerning related fields of science and technology, see Glossary of chemistry terms, Glossary of astronomy, Glossary of areas of mathematics, and Glossary of engineering.
Gerhard Rempe is a German physicist, Director at the Max Planck Institute of Quantum Optics and Honorary Professor at the Technical University of Munich. He has performed pioneering experiments in atomic and molecular physics, quantum optics and quantum information processing.
Howard John Carmichael is a British-born New Zealand theoretical physicist specialising in quantum optics and the theory of open quantum systems. He is the Dan Walls Professor of Physics at the University of Auckland and a principal investigator of the Dodd-Walls Centre. Carmichael has played a role in the development of the field of quantum optics and is particularly known for his Quantum Trajectory Theory (QTT) which offers a more detailed view of quantum behaviour by making predictions of single events happening to individual quantum systems. Carmichael works with experimental groups around the world to apply QTT to experiments on single quantum systems, including those contributing to the development of quantum computers. He is a Fellow of Optical Society of America, the American Physical Society and the Royal Society of New Zealand. He was awarded the Max Born Award in 2003, the Humboldt Research Award in 1997 and the Dan Walls Medal of the New Zealand Institute of Physics in 2017. In 2015, he was recognised as an Outstanding Referee by the American Physical Society.
Halina Rubinsztein-Dunlop is a professor of physics at the University of Queensland and an Officer of the Order of Australia. She has led pioneering research in atom optics, laser micro-manipulation using optical tweezers, laser enhanced ionisation spectroscopy, biophysics and quantum physics.
The I. I. Rabi Prize in Atomic, Molecular, and Optical Physics is given by the American Physical Society to recognize outstanding work by mid-career researchers in the field of atomic, molecular, and optical physics. The award was endowed in 1989 in honor of the physicist I. I. Rabi and has been awarded biannually since 1991.
John Morrissey Doyle is an American physicist working in the field of Atomic, Molecular, and Optical (AMO) physics and Precision Particle Physics. He is the Henry B. Silsbee Professor of Physics, Director of the Japanese Undergraduate Research Exchange Program (JUREP), Co-Director of the Harvard Quantum Initiative as well as Co-director of the Ph.D. Program in Quantum Science and Engineering at Harvard University.
