Department Research Activities:
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 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. 
• 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. 
• Zvonimir Dogic  and his group are focused on elucidating the fundamental forces that govern behavior of diverse soft and biological materials. Particular focus is on creating bulk materials that are continuously driven away from equilibrium by collective motion of thousands of biological nanomachines. Long term goal is to create a new class of active synthetic matter that can recapitulate many of features that have so far been mainly found in living organisms. 
• 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.
• Ania Bleszynski Jayich uses scanning probe microscopy to study quantum effects on the nanoscale in condensed matter systems. She is developing novel quantum sensors based on defects in diamond to probe single spins, single electrons, and their interactions. Application of interest include quantum computing, materials based device physics, and biology.
• Chenhao Jin  develops optical spectroscopy and imaging techniques to "watch" quantum phenomena in space and time. His current research interest lies in the interplay between dimensionality, many-body interaction, fluctuations and competing orders. Examples include two-dimensional (2D) materials, moiré superlattices, spin systems, strongly correlated materials, topological systems, and their combinations.
• 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.
• Ben Mazin develops energy-resolving photon detectors based on superconducting microresonators.  His group then integrates these detectors into cameras for large optical telescopes, and uses the cameras to perform astronomical observations on a variety of science targets.
• 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.
• David Weld uses the techniques of experimental ultracold atomic physics to seek solutions to important outstanding problems in condensed matter physics and many-body quantum mechanics.  Research interests of his group include quantum simulation, optical lattices, trapping of alkali and alkaline earth atoms, novel quantum phases, nonequilibrium dynamics, new cooling techniques, analogies between condensed matter and atomic physics, quantum metrology, and micron-scale force sensing.
• Pierre Wiltzius' research interests include soft condensed matter and complex fluids, e.g., polymers, colloids, liquid crystals, and his current research is focused on developing new fabrication techniques for photonic crystals including colloidal self-assembly and multi-beam interference lithography. He was also involved in plastic transistors on flexible substrates for various applications, including electronic paper. Prof. Wiltzius is not taking on new graduate students, undergrads or postdocs at this time.
• Andrea Young investigates the properties of novel electronic states in quantum materials characterized by reduced dimensionality, strong correlations, or both. Currently, he is interested in the interplay between symmetry, topology, and correlations in low dimensional materials such as graphene and metal dichalcogenides. His group develops fabrication techniques to create heterostructures out of atomically thin materials, as well as customized cryogenic measurements to access the electrical, magnetic, and thermal properties of these fragile electronic states