The spin degree of freedom for donor nuclei in silicon have exceptionally long coherence times making them useful as either quantum bits (qubits) or long-lived quantum memories. Nuclear spins are hard to control in nanoscale devices since they are thought to only be coherently manipulated using magnetic fields, which are hard to confine. In this collaboration, researchers in IRG3 identify two new physical mechanisms that allow for manipulation of nuclear spins using only electric fields.

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 their bulk values.

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 and B. In comparison to melt-crystallized PE (Fig.

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. By examining electronic behavior on the surface of bismuth at high magnetic field, the Princeton MRSEC group showed that a combination of strain and electron-electron interactions lifts the degeneracy of electronic states in this 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. The Princeton MRSEC group has observed this new effect (called the chiral anomaly) in two distinct topological metals, Na3Bi and GdPtBi (1,2).

Graduate Students for Diversity in Science is composed of an interdisciplinary group of young scientists at the University of California, Santa Barbara (UCSB). The cornerstone of the group lies in its recognition of the cultural heritage and diversity of many exceptional scientists who have set foundations through research, service, and leadership in their respective disciplines and across many boundaries. GSDS aims to promote participation in the science, technology, engineering and math (STEM) fields and foster an inclusive atmosphere that celebrates diversity.

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.