In physics, the Tsallis entropy is a generalization of the standard Boltzmann–Gibbs entropy. It is proportional to the expectation of the q-logarithm of a distribution.
In magnetism, a nanomagnet is a nanoscopic scale system that presents spontaneous magnetic order (magnetization) at zero applied magnetic field (remanence).
A strangelet is a hypothetical particle consisting of a bound state of roughly equal numbers of up, down, and strange quarks. An equivalent description is that a strangelet is a small fragment of strange matter, small enough to be considered a particle. The size of an object composed of strange matter could, theoretically, range from a few femtometers across to arbitrarily large. Once the size becomes macroscopic, such an object is usually called a strange star. The term "strangelet" originates with Edward Farhi and Robert Jaffe in 1984. It has been theorized that strangelets can convert matter to strange matter on contact. Strangelets have also been suggested as a dark matter candidate.
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-.
Multi-particle collision dynamics (MPC), also known as stochastic rotation dynamics (SRD), is a particle-based mesoscale simulation technique for complex fluids which fully incorporates thermal fluctuations and hydrodynamic interactions. Coupling of embedded particles to the coarse-grained solvent is achieved through molecular dynamics.
Active matter is matter composed of large numbers of active "agents", each of which consumes energy in order to move or to exert mechanical forces. Such systems are intrinsically out of thermal equilibrium. Unlike thermal systems relaxing towards equilibrium and systems with boundary conditions imposing steady currents, active matter systems break time reversal symmetry because energy is being continually dissipated by the individual constituents. Most examples of active matter are biological in origin and span all the scales of the living, from bacteria and self-organising bio-polymers such as microtubules and actin, to schools of fish and flocks of birds. However, a great deal of current experimental work is devoted to synthetic systems such as artificial self-propelled particles. Active matter is a relatively new material classification in soft matter: the most extensively studied model, the Vicsek model, dates from 1995.
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.
Self-propelled particles (SPP), also referred to as self-driven particles, are terms used by physicists to describe autonomous agents, which convert energy from the environment into directed or persistent random walk. Natural systems which have inspired the study and design of these particles include walking, swimming or flying animals. Other biological systems include bacteria, cells, algae and other micro-organisms. Generally, self-propelled particles often refer to artificial systems such as robots or specifically designed particles such as swimming Janus colloids, bimetallic nanorods, nanomotors and walking grains. In the case of directed propulsion, which is driven by a chemical gradient, this is referred to as chemotaxis, observed in biological systems, e.g. bacteria quorum sensing and ant pheromone detection, and in synthetic systems, e.g. enzyme molecule chemotaxis and enzyme powered hard and soft particles.
The Vicsek model is a mathematical model used to describe active matter. One motivation of the study of active matter by physicists is the rich phenomenology associated to this field. Collective motion and swarming are among the most studied phenomena. Within the huge number of models that have been developed to catch such behavior from a microscopic description, the most famous is the model introduced by Tamás Vicsek et al. in 1995.
Allan H. MacDonald is a theoretical condensed matter physicist and the Sid W. Richardson Foundation Regents Chair Professor of Physics at The University of Texas at Austin. His research interests are centered on the electronic properties of electrons in metals and semiconductors. He is well known for his work on correlated many-electron states in low-dimensional systems. In 2020, he became one of the laureates of the Wolf Prize in Physics, for predicting the magic angle that turns twisted bilayer graphene into a superconductor.
Ajay Kumar Sood is an Indian physicist and researcher currently serving as the 4th Principal Scientific Adviser to the Government of India.
Raymond Ethan Goldstein FRS FInstP is the Alan Turing Professor of Complex Physical Systems in the Department of Applied Mathematics and Theoretical Physics (DAMTP) at the University of Cambridge and a Fellow of Churchill College, Cambridge.
Bedangadas Mohanty is an Indian physicist specialising in experimental high energy physics, and is affiliated to National Institute of Science Education and Research, Bhubaneswar. He has been awarded the Infosys Prize in Physical Sciences for 2021 that was announced on 2 December 2021. He was awarded the Shanti Swarup Bhatnagar Prize for Science and Technology in 2015, the highest science award in India, in the physical sciences category. He has been elected as the fellow of the Indian National Science Academy, New Delhi, Indian Academy of Sciences, Bangalore and National Academy of Sciences, India. In 2020, he was elected as a fellow of American Physical Society.
Hyperuniform materials are characterized by an anomalous suppression of density fluctuations at large scales. More precisely, the vanishing of density fluctuations in the long-wave length limit distinguishes hyperuniform systems from typical gases, liquids, or amorphous solids. Examples of hyperuniformity include all perfect crystals, perfect quasicrystals, and exotic amorphous states of matter.
An active fluid is a densely packed soft material whose constituent elements can directly inject and dissipate energy. Examples include dense suspensions of bacteria, microtubule networks or artificial swimmers. These materials come under the broad category of active matter and differ significantly in properties when compared to passive fluids, which can be described using Navier-Stokes equation. Even though systems describable as active fluids have been observed and investigated in different contexts for a long time, scientific interest in properties directly related to the activity has emerged only in the past two decades. These materials have been shown to exhibit a variety of different phases ranging from well ordered patterns to chaotic states. Recent experimental investigations have suggested that the various dynamical phases exhibited by active fluids may have important technological applications.
Maria Cristina Marchetti is an Italian-born, American theoretical physicist specializing in statistical physics and condensed matter physics. In 2019, she received the Leo P. Kadanoff Prize of the American Physical Society. She held the William R. Kenan, Jr. Distinguished Professorship of Physics at Syracuse University, where she was the director of the Soft and Living Matter program, and chaired the department 2007–2010. She is currently Professor of Physics at the University of California, Santa Barbara.
Dov I. Levine is an American-Israeli physicist, known for his research on quasicrystals, soft condensed matter physics, and statistical mechanics out of equilibrium.
Elbio Rubén Dagotto is an Argentinian-American theoretical physicist and academic. He is a distinguished professor in the department of physics and astronomy at the University of Tennessee, Knoxville, and Distinguished Scientist in the Materials Science and Technology Division at the Oak Ridge National Laboratory.
Leo Radzihovsky is a Russian American condensed matter physicist and academic serving as a professor of Distinction in Physics at the University of Colorado Boulder.
John Joseph Toner is an American physicist and professor emeritus at the University of Oregon in Eugene, Oregon. Toner's broad interests in condensed matter physics span the gamut from topics in "statistical physics and the hydrodynamics of systems ranging from hard to soft condensed matter and from passive to active systems".
