The focus of condensed matter and materials physics (CMMP) is understanding how underlying laws unfold in the physical world around us. A typical system consists of many individual particles or units which have coalesced into a medium with new, often surprising, properties. Superconductors and liquid crystals are two classic examples. In recent years, CMMP has grown to be tremendously broad. Topics being actively pursued include, for instance, strong correlations between electrons in novel materials, quantum phenomena in low dimensional systems, phases and dynamics of soft matter, quantum phase transitions, far from equilibrium phenomena, and granular materials. Here at Duke, we focus on two areas of condensed matter and materials physics: *quantum phenomena in nanometer scale systems*, and* nonlinear and complex systems.*

Experiments on these topics are typically carried out by individual students who have the opportunity to explore all aspects of a project, including design, construction, and data analysis. Theoretical progress relies on the adaptation and extension of many-body theory and dynamical systems theory, distilling the crucial features of the system into models that can be studied either analytically or numerically.

##### Nanoscience / Quantum Emergent Phenomena

Fundamental interest in nanophysics -- the physics of small, nanometer scale, bits of solid -- stems from the ability to control and probe systems on length scales larger than atoms but small enough that the averaging inherent in bulk properties has not yet occurred. Using this ability, entirely unanticipated phenomena can be uncovered on the one hand, and the microscopic basis of bulk phenomena can be probed on the other. Additional interest comes from the many links between nanophysics and nanotechnology. Key issues currently in nanophysics include how novel quantum collective behavior emerges from simple elements, connections to quantum information (entanglement), and the role of topological states in a variety of settings. For descriptions of particular projects, see the webpages arranged by faculty (Baranger, Chandrasekharan, Chang, Finkelstein, Hastings, and Teitsworth).

##### Nonlinear and Complex Systems

The challenge in this area is to discover and characterize the collective behavior of complex systems, and to uncover the principles that connect the physics and logic of interactions between parts to the properties of the full system. This rapidly developing research area relies heavily on the concepts and language of nonlinear dynamics, and the evolution of this area of research at Duke began with physicists, geophysicists, mathematicians, and engineers recognizing they shared a common language. For descriptions of particular projects, see the webpages arranged by faculty (Behringer, Palmer, Socolar, and Teitsworth).

##### Home Pages for Faculty in Condensed Matter Physics

Harold U. Baranger: Theory of quantum phenomena at the nanometer scale; many-body effects in quantum dots and wires; conduction through single molecules; quantum computing; quantum phase transitions. See the Baranger Group lab site.

Robert P. Behringer: Experiments on instabilities and pattern formation in fluids; flow, jamming, and stress patterns in granular materials. See the Behringer Lab site.

Shailesh Chandrasekharan: Theoretical studies of quantum phase transitions using quantum Monte Carlo methods; lattice QCD (see nuclear and particle theory page).

Albert M.Chang: Experiments on quantum transport at low temperature; one-dimensional superconductivity; dilute magnetic semiconductor quantum dots; Hall probe scanning.

Gleb Finkelstein: Experiments on quantum transport at low temperature; carbon nanotubes; Kondo effect; cryogenic scanning microscopy; self-assembled DNA templates. See the Electronic Nanostructures Group site.

Sara Haravifard: Exploring novel collective phenomena in quantum magnets and superconductors by means of neutron and x-ray scattering techniques; Investigating quantum critical phenomena at extreme environmental conditions of ultra-low temperature, high magnetic field, and high pressure; Materials by Design: synthesis, single crystal growth and characterization of correlated electron systems, quantum magnets and high-temperature superconductors.

Richard G. Palmer: Theoretical models of learning and memory in neural networks; glassy dynamics in random systems with frustrated interactions.

Maiken H. Mikkelsen: Experiments in Nanophysics & Condensed Matter Physics

Joshua E. S. Socolar: Theory of dynamics of complex networks; Modeling of gene regulatory networks; Structure formation in colloidal systems; Tiling theory and nonperiodic long-range order.

Stephen W. Teitsworth: Experiments on nonlinear dynamics of currents in semiconductors.