Condensed Matter Experimental Physics

Condensed matter physics is a highly diverse area of research, ranging from innovative studies of the basic properties of novel materials, the study of complex fluids and nonlinear phenomena, to the development and study of nanometer-scale electronic, spintronic, superconducting and optical systems. It forms the basis for the exploration of new materials such as carbon nanotubes and semiconducting nanowires, as well as the basis for the next generation of electronic devices. Much of the modern technology that energizes today's society (e.g. electronics, magnetics, and photonics) is rooted in condensed matter physics.

The advanced technology required to pursue research in this field is provided at UCSB by a number of unique shared research facilities. These include a variety of molecular beam epitaxy chambers for atomically-precise sample fabrication, a world-class clean room and nanofabrication lab for turning wafers into devices, both research and student machine shops, and a free-electron laser facility for exploring terahertz science and technology. In addition, our students have access to the wide range of shared experimental facilities within the Materials Research Laboratory and the new California Nanosystems Institute.

The breadth and impact of condensed matter physics makes it a central part of any excellent physics department. The broad range of topics also makes collaborative efforts with other departments and colleges a must. Active collaborations between UCSB condensed-matter physics groups and other departments include Electrical and Computer Engineering (ECE), Mechanical Engineering, Chemical Engineering, Materials Science, Chemistry and Biology. Research topics include both pure condensed matter science as well as applied physics.

Research efforts within the UCSB Condensed Matter Physics Group include:

• Guenter Ahlers focuses on the study of non-linear systems far from equilibrium, with an emphasis on pattern formation, and on turbulence in a fluid heated from below.
• Jim Allen explores terahertz transport in quantum structures, with current emphasis on Bloch oscillation in superlattices and their use in coherent, inversion-less terahertz lasers. Plasmonic devices are also developed as sensitive tunable, narrow-band incoherent terahertz detectors. Efforts also center on developing a novel terahertz circular dichroism spectroscopy to detect and measure the functionally relevant macromolecular motions of biopolymers. 
• David Awschalom explores optical and magnetic interactions in semiconductor quantum structures, spin dynamics and coherence in condensed matter systems ("spintronics"), information processing in hybrid molecular nanostructures, and implementations of quantum computation in the solid state. He uses a variety of low temperature femtosecond-resolved magneto-optical spatiotemporal spectroscopies aimed at exploring charge and spin motion in the quantum domain.
• Dirk Bouwmeester investigates topics related to quantum information science and quantum decoherence using entangled photon states and solid-state cavity quantum electro-dynamics.
• David Cannell uses optical techniques (laser light scattering and quantitative shadowgraph measurements) to study fundamental problems in statistical and thermal physics. He is presently working on an experiment to study the effect of gravity on fluctuations in a layer of fluid subjected to a temperature gradient. 
• Andrew Cleland pursues research in nanometer scale mechanical and electronic devices. Areas of interest include bolometric energy detection, nanoscale calorimetry, quantum computing, and microfluidic systems. He also has interests in nonlinear effects in mechanical systems, and in exploring new materials for achieving new capabilities in his device applications.
• Beth Gwinn studies hybrid organic-inorganic structures, magnetism in semiconductors, and quantum Hall physics. Her group uses magneto-transport measurements, magnetometry and surface spectroscopies to investigate how the binding of organic molecules to solid-state materials leads to new electric and magnetic properties at the organic-inorganic interface. 
• Alan Heeger develops the fundamental physics that determines the electronic and nonlinear optical properties of semiconducting and metallic organic polymers, with the goal of making these novel materials available for technological applications.
• John Martinis explores the physics of superconducting devices, focusing on achieving very low noise and highsensitivity performance. His primary interest at present is to build a quantum computer based on Josephson junction quantum bits.
• Mark Sherwin pursues the experimental implementation of quantum information processing in semiconductors, the study of few- and many-body quantum systems coherently driven far from equilibrium, the development of fast and sensitive detectors for THz radiation, and ultrafast modulation of light for optical communications.