N. Peter Armitage (born 1971) is an American physicist who is currently a Professor of Physics and Astronomy at The Johns Hopkins University. His research centers on understanding material systems which exhibit coherent quantum effects at low temperatures, like superconductors and quantum magnetism. His principal scientific interest is understanding how is it that large ensembles of strongly interacting, but fundamentally simple particles like electrons in solids act collectively to exhibit complex emergent quantum phenomena. He exploits and develops techniques using low frequency microwave and THz range radiation that probe these systems at their natural frequency scales. The material systems of interest require new measurement techniques as their relevant frequencies typically fall between the range of usual optical and electronic methods.
Armitage received a BS degree from Rutgers University and a PhD from Stanford University in 2002. He did postdoctoral work at the University of California, Los Angeles and the University of Geneva. He joined the faculty of Johns Hopkins in 2006 as an assistant professor of physics and is currently a Professor of Physics and Astronomy.
He is known primarily for is work on superconductivity, magnetism, disordered systems, and topological materials. During his PhD., he did seminal work with angle resolved photoemission on the electron-doped cuprates. At Johns Hopkins, his group has measured the quantized magnetoelectric "axion" response of topological insulators. [1] [2] [3] [4] This quantized response is the 3D equivalent in topological insulators of the quantized Hall plateaus found in quantum Hall systems. Other work demonstrated the existence of Kramers-Wannier duality in Kitaev chains. [5]
Armitage has been a recipient of a DARPA Young Faculty Award, an NSF Career Award, a Sloan Research Fellowship, was a three time Kavli Frontiers Fellow, the William Spicer Award from the Stanford Synchrotron Radiation Laboratory, the William L. McMillan Award from the University of Illinois, the 2016 Genzel Prize, and was the 2019 Nakamura Lecturer at the UCSB Materials Department. He is a member of the Quantum Materials Program at the Canadian Institute for Advanced Research (CIFAR) and was the co-chair of the 2014 Gordon Research Conference in Correlated Electron Systems.
Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases, that arise from electromagnetic forces between atoms and electrons. More generally, the subject deals with condensed phases of matter: systems of many constituents with strong interactions among them. More exotic condensed phases include the superconducting phase exhibited by certain materials at extremely low cryogenic temperatures, the ferromagnetic and antiferromagnetic phases of spins on crystal lattices of atoms, the Bose–Einstein condensates found in ultracold atomic systems, and liquid crystals. Condensed matter physicists seek to understand the behavior of these phases by experiments to measure various material properties, and by applying the physical laws of quantum mechanics, electromagnetism, statistical mechanics, and other physics theories to develop mathematical models and predict the properties of extremely large groups of atoms.
In physics, the Kondo effect describes the scattering of conduction electrons in a metal due to magnetic impurities, resulting in a characteristic change i.e. a minimum in electrical resistivity with temperature. The cause of the effect was first explained by Jun Kondo, who applied third-order perturbation theory to the problem to account for scattering of s-orbital conduction electrons off d-orbital electrons localized at impurities. Kondo's calculation predicted that the scattering rate and the resulting part of the resistivity should increase logarithmically as the temperature approaches 0 K. Extended to a lattice of magnetic impurities, the Kondo effect likely explains the formation of heavy fermions and Kondo insulators in intermetallic compounds, especially those involving rare earth elements such as cerium, praseodymium, and ytterbium, and actinide elements such as uranium. The Kondo effect has also been observed in quantum dot systems.
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.
In physics, topological order is a kind of order in the zero-temperature phase of matter. Macroscopically, topological order is defined and described by robust ground state degeneracy and quantized non-abelian geometric phases of degenerate ground states. Microscopically, topological orders correspond to patterns of long-range quantum entanglement. States with different topological orders cannot change into each other without a phase transition.
In particle physics, a relativistic particle is an elementary particle with kinetic energy greater than or equal to its rest-mass energy given by Einstein's relation, , or specifically, of which the velocity is comparable to the speed of light .
Subir Sachdev is Herchel Smith Professor of Physics at Harvard University specializing in condensed matter. He was elected to the U.S. National Academy of Sciences in 2014, received the Lars Onsager Prize from the American Physical Society and the Dirac Medal from the ICTP in 2018, and was elected Foreign Member of the Royal Society ForMemRS in 2023. He was a co-editor of the Annual Review of Condensed Matter Physics 2017–2019, and is Editor-in-Chief of Reports on Progress in Physics 2022-.
A topological insulator is a material whose interior behaves as an electrical insulator while its surface behaves as an electrical conductor, meaning that electrons can only move along the surface of the material.
Piers Coleman is a British-born theoretical physicist, working in the field of theoretical condensed matter physics. Coleman is professor of physics at Rutgers University in New Jersey and at Royal Holloway, University of London.
Frederick Duncan Michael Haldane, known as F. Duncan Haldane, is a British-born physicist who is currently the Sherman Fairchild University Professor of Physics at Princeton University. He is a co-recipient of the 2016 Nobel Prize in Physics, along with David J. Thouless and J. Michael Kosterlitz.
In quantum mechanics, fractionalization is the phenomenon whereby the quasiparticles of a system cannot be constructed as combinations of its elementary constituents. One of the earliest and most prominent examples is the fractional quantum Hall effect, where the constituent particles are electrons but the quasiparticles carry fractions of the electron charge. Fractionalization can be understood as deconfinement of quasiparticles that together are viewed as comprising the elementary constituents. In the case of spin–charge separation, for example, the electron can be viewed as a bound state of a 'spinon' and a 'holon ', which under certain conditions can become free to move separately.
Shoucheng Zhang was a Chinese-American physicist who was the JG Jackson and CJ Wood professor of physics at Stanford University. He was a condensed matter theorist known for his work on topological insulators, the quantum Hall effect, the quantum spin Hall effect, spintronics, and high-temperature superconductivity. According to the National Academy of Sciences:
He discovered a new state of matter called topological insulator in which electrons can conduct along the edge without dissipation, enabling a new generation of electronic devices with much lower power consumption. For this ground breaking work he received numerous international awards, including the Buckley Prize, the Dirac Medal and Prize, the Europhysics Prize, the Physics Frontiers Prize and the Benjamin Franklin Medal.
James P. Eisenstein is an American physicist noted for his experimental research on strongly interacting two-dimensional electron systems. He is currently the Frank J. Roshek Professor of Physics and Applied Physics, Emeritus, at the California Institute of Technology.
Xue Qikun is a Chinese physicist. He is a professor of Tsinghua University, Beijing. He has done much work in condensed matter physics, especially on superconductors and topological insulators. In 2013, Xue was the first to achieve the quantum anomalous Hall effect (QAHE), an unusual orderly motion of electrons in a conductor, in his laboratory at Tsinghua University. Xue is a member of the Chinese Academy of Sciences, vice president for research of Tsinghua University, and director of State Key Lab of Quantum Physics. In 2016, he was one of the first recipients of the new Chinese Future Science Prize for experimental discovery of high-temperature superconductivity at material interfaces and the QAHE. This award has been described as "China's Nobel Prize".
J. C. Séamus Davis is an Irish physicist whose research explores the world of macroscopic quantum physics. Davis concentrates upon the fundamental physics of exotic states of electronic, magnetic, atomic and space-time quantum matter. A specialty is development of innovative instrumentation to allow direct atomic-scale visualization or perception of the quantum many-body phenomena that are characteristic of these states.
Aharon Kapitulnik is an Israeli-American experimental condensed matter physicist working at Stanford University. He is known primarily for his work on strongly correlated electron systems, low dimensional electronic systems, unconventional superconductors, topological superconductors, superconductivity and magnetism, transport in bad metals and precision measurements.
Suchitra Sebastian is a condensed matter physicist at Cavendish Laboratory, University of Cambridge. She is known for her discoveries of exotic quantum phenomena that emerge in complex materials. In particular, she is known for the discovery of unconventional insulating materials which display simultaneous conduction-like behaviour. In 2022 she was awarded the New Horizons in Physics Prize by the Breakthrough Foundation. She was named as one of thirty Exceptional Young Scientists by the World Economic Forum in 2013, one of The Next Big Names in Physics by the Financial Times in 2013, and spoke at the World Economic Forum at Davos in 2016.
In physics, magnetic topological insulators are three dimensional magnetic materials with a non-trivial topological index protected by a symmetry other than time-reversal. This type of material conducts electricity on its outer surface, but its volume behaves like an insulator.
Amalia Patanè is an Italian physicist who is Professor of Physics at the University of Nottingham and UK Director of the European Magnetic Field Laboratory.
Adriana Moreo is an Argentine-American condensed matter physicist whose research involves the computer simulation of superconductors, oxides of transition metals, graphene, and other strongly correlated materials. She is a professor in the Department of Physics & Astronomy at the University of Tennessee and a member of the research staff in the Materials Science and Technology Division of the Oak Ridge National Laboratory.