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Andre Geim coauthored measurements showing that electric charge carriers in graphene can behave as effectively massless quasiparticles described by the Dirac equation. The 2005 experiments found an unusual sequence of quantum Hall effect plateaus and an oscillation phase associated with Berry phase. Here the Dirac description concerns low-energy quasiparticles in a carbon lattice, rather than free electrons acquiring zero rest mass. The results connect a readily contacted material with concepts usually introduced in relativistic quantum mechanics.^[ref]

A physicist researching condensed matter physics, including graphene.^[ref]

Condensed matter comprises physical systems such as solids and liquids in which interactions among many constituents determine the observed properties. The term refers to the material system; condensed matter physics studies its structure, dynamics and phases.

A crystal illustrates the change of viewpoint. Its chemical atoms can have collective vibrational modes described as phonons, while its electronic response can involve energy bands rather than isolated-atom energy levels. Collective excitations and phase transitions show why a many-constituent system can display useful organizing principles that are not apparent from one atom alone.

A condensed matter physicist studies condensed matter physics through mathematical theory, observation or experiment. The field determines the relevant physical systems and measurements, while the individual biographies below connect particular contributions with their scientific ideas.

Condensed matter physics studies the collective behavior of matter with many interacting constituents, especially solids and liquids. Crystal structure, electron interactions and thermal motion produce properties that are not apparent from one isolated atom.

A phonon describes a collective lattice vibration, while superconductivity involves a coherent many-electron state. The same microscopic ingredients can produce different phases as temperature, pressure or composition changes. Experiments connect structural, transport, magnetic and spectroscopic measurements with models of those phases.

Duncan Haldane constructed a two-dimensional lattice model with quantized Hall conductivity without a net applied magnetic field. The Haldane model separates the topological mechanism of the quantum Hall effect from the usual formation of Landau levels in a uniform field. Changing model parameters closes and reopens an energy gap, separating phases with different Hall responses. This provides a compact theoretical example in which the global structure of occupied electronic states determines a measurable transport coefficient.^[ref]

A physicist researching condensed matter physics.^[ref]

John Hopfield showed how an interacting neural network can retrieve a stored pattern from incomplete information. His 1982 model uses asynchronous updates of simple units, with symmetric couplings allowing an energy-like function to decrease as the network evolves. Stored patterns act as attractors, so the collective dynamics can correct some corrupted input rather than requiring an exact address. The physical analogy connects stable states of an interacting system with associative computation; convergence to a stable state does not by itself guarantee retrieval of the intended pattern.^[ref]

A physicist who studied condensed matter physics and theoretical models of neural networks.^[ref]

Konstantin Novoselov coauthored experiments showing that atomically thin graphene can operate as an electrically controlled conducting sheet. A gate changes its carrier population, making a single carbon layer an accessible two-dimensional electron gas. The 2004 work demonstrated a field effect and ballistic transport over submicrometre distances even at room temperature. It turned an isolated atomic layer into a device for testing transport in two dimensions.^[ref]

A physicist researching experimental condensed matter physics.^[ref]

A physicist researching condensed matter physics.^[ref]

Pierre-Gilles de Gennes developed connections between the physics of polymers and liquid crystals, using ideas from critical phenomenon studies. Long molecules and orientationally ordered fluids can have large collective responses even when their microscopic constituents differ greatly. Scaling and order-parameter descriptions identify which large-scale behavior follows from symmetry and connectivity rather than detailed molecular chemistry. His account of soft matter emphasizes this ability to move useful physical ideas between seemingly different materials, while retaining the experimental phenomena that distinguish them.^[ref]

A physicist who held the condensed matter physics chair at Collège de France from 1971 to 2004.^[ref]

A physicist and author of teaching texts on condensed matter physics and quantum matter. His treatment of linear response develops a useful progression: calculate how independent electrons respond to a perturbing potential, then include the additional field produced by their own rearranged charge. The resulting random phase approximation explains screening effect as a self-consistent response, giving students a route from a microscopic model to the collective electrical behavior of a material.^[ref]

Nuclear and particle physics and condensed matter physics are core; further papers or projects are selected. BA and MPhys routes differ.