Block copolymers, which self-assemble into nanostructures due to the incompatibility of each block, have generated intense scientific interest and are used in a myriad of important technologies. In such systems, the majority of the macromolecules can lie within a few nanometers of an internal interface, within a region where the dynamics and mechanical properties can be highly modified from th
We exploited Matrix Assited Pulsed Laser Evaporation (MAPLE) to deposit polyethylene from a quasi-vapor phase at a controlled substrate temperature, to crystallize polymers under confinement at a wide range of target crystallization temperature, Tc. The team showed the remarkable controllability of the semi-crystalline structure of PE by MAPLE with the control of substrate temp.; see Figure A
Interactions among electrons can give rise to a variety of exotic quantum phases in solids. An intriguing example is the formation of “nematic” electronic states, whose wave functions break the rotational symmetry of the host material.
Electrons in topological materials behave like massless particles (called Weyl fermions). They are either right- or left-handed (the spins are locked parallel or antiparallel to their velocity). In parallel applied electric and magnetic fields, one population grows while the other shrinks. This leads to a new kind of electrical current called an “axial” current.
Graduate Students for Diversity in Science is composed of an interdisciplinary group of young scientists at the University of California, Santa Barbara (UCSB).
The DNP-NMR technique in the MRSEC Shared Experimental Facilities allows the selective measurement of surface species, in addition to enabling large sensitivity enhancements. The biradicals serve only to act as an antenna for the microwaves. Very small quantities of biradicals are introduced into the sample, which do not change the surface chemistry that results from hydration.
With declining numbers of STEM degrees and limited diversity in the STEM workforce, there is a need for expansion of research opportunities for undergraduate and high school students, in particular those from underrepresented groups.
A feasible optical interconnect on a silicon complementary metal-oxide-semiconductor chip demands epitaxial growth and monolithic integration of diode lasers and optical detectors with guided wave components on a (001) Si wafer, with all the components preferably operating in the wavelength range of 1.3–1.55 μm at room temperature.
Finely patterned surfaces, known as metasurfaces, can control light with unprecedented ability. Unlike traditional optical elements, metasurfaces derive their optical properties from their subwavelength texture rather than their shape.
From the ancient art of origami to modern meta-materials research, a central goal has been to develop the ability to convert a flat, stiff sheet into its final three-dimensional shape with just one single folding motion. Except for a few known cases, general design rules for the required patterns of creases have been elusive.
