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Highlights

Highlights

Local density of states on the surface of bismuth at magnetic field B = 12.9 T and energy E = 780 µeV. Dark concentric ellipses reflect the shape of individual electronic states. The anisotropy points in different directions for states at other energies.
Local density of states on the surface of bismuth at magnetic field B = 12.9 T and energy E = 780 µeV. Dark concentric ellipses reflect the shape of individual electronic states. The anisotropy points in different directions for states at other energies.
Aug 21, 2017
Princeton University

Real-space imaging of a nematic quantum liquid

B. E. Feldman1, M. T. Randeria1, A. Gyenis1, F. Wu2, H. Ji1, R. J. Cava1, A. H. MacDonald2, A. Yazdani1 1Princeton University 2University of Texas at Austin
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.
Figure 1: Curves showing how the resistance at selected temperatures falls with increasing magnetic field B in GdPtBi. The decrease reflects the emergence of the axial current, an effect called the chiral anomaly (Ref. 2). The curves in Na3Bi (1) are remarkably similar.
Figure 1: Curves showing how the resistance at selected temperatures falls with increasing magnetic field B in GdPtBi. The decrease reflects the emergence of the axial current, an effect called the chiral anomaly (Ref. 2). The curves in Na3Bi (1) are remarkably similar.
Aug 21, 2017
Princeton University

Chiral anomaly observed as an axial current in two topological quantum materials

M. Hirschberger (Princeton), J. Xiong (Princeton), S. Kushwaha (Princeton), A. Bernevig (Princeton), R. J. Cava (Princeton), and N. P. Ong (Princeton)
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).
(Top) Winter 2017‒Dow Distinguished Lecturer Temple Grandin speaking to a packed room. (Bottom): UCSB graduate & California State University students mingling during lunch
(Top) Winter 2017‒Dow Distinguished Lecturer Temple Grandin speaking to a packed room. (Bottom): UCSB graduate & California State University students mingling during lunch
Jul 19, 2017
University of California, Santa Barbara

Graduate Students for Diversity in Science at UCSB

Ram Seshadri, UCSB  
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.
DNP Nuclear Magnetic Resonance
DNP Nuclear Magnetic Resonance
Jul 19, 2017
University of California, Santa Barbara

DNP Nuclear Magnetic Resonance

Ram Seshadri, 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.
(Top Left): 2016 C-PHOM High School Research Program Participants. (Bottom Left): 2016 High School student working in the lab with Grad mentor. (Right): 2016 High School student working in the lab.
(Top Left): 2016 C-PHOM High School Research Program Participants. (Bottom Left): 2016 High School student working in the lab with Grad mentor. (Right): 2016 High School student working in the lab.
Jul 12, 2017
University of Michigan - Ann Arbor

From High School to Professional Scientist: Developing a Pipeline

Akesha C. Moore* and Rachel S. Goldman** *EECS Department, **MSE Department, University of Michigan
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) SEM image of a nanowire array. (b) SEM image of the fabricated photonic integrated circuit. (c) TEM images of single nanowires showing the formation of quantum dot-like nanostructures in the InN disk regions.
(a) SEM image of a nanowire array. (b) SEM image of the fabricated photonic integrated circuit. (c) TEM images of single nanowires showing the formation of quantum dot-like nanostructures in the InN disk regions.
Jul 12, 2017
University of Michigan - Ann Arbor

1.3µm Optical Interconnect on Silicon: A Monolithic III-Nitride Nanowire Array Photonic Integrated Circuit

Prof. Pallab Bhattacharya, University of Michigan, Ann Arbor
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.
Generating Accelerating Light with Metasurfaces
Generating Accelerating Light with Metasurfaces
Jul 12, 2017
University of Michigan - Ann Arbor

Generating Accelerating Light with Metasurfaces

University of Michigan (U-M) and Purdue University (P-U)
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.
New Design Principles for Self-Folding Materials
New Design Principles for Self-Folding Materials
Jul 10, 2017
University of Chicago

New Design Principles for Self-Folding Materials

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.  
Sample images exhibit three regimes: a subcritical regime before the transition; a frozen regime beyond the critical point where the fluctuation remains low; and a growth regime in which fluctuation increases and saturates, indicating domain formation.
Sample images exhibit three regimes: a subcritical regime before the transition; a frozen regime beyond the critical point where the fluctuation remains low; and a growth regime in which fluctuation increases and saturates, indicating domain formation.
Jul 10, 2017
University of Chicago

Universal Dynamics of Bosons Across a Quantum Phase Transition

A Bose-Einstein condensate, when shaken appropriately, shows universal dynamics at a ferromagnetic quantum critical point. By ramping the modulation strength, the emergence and growth of the pseudo-spin fluctuations are universal in the normalized coordinate (bottom graphic, squares), and are in good agreement with theoretical calculations (bottom graph. Line). 
An octobot
An octobot
Jul 10, 2017
Harvard University

An Integrated Design and Fabrication Strategy for Entirely Soft, Autonomous Robots

Jennifer A. Lewis (BioEng), George M. Whitesides (Chem) and Robert J. Wood (ElecEng)
Soft robots possess many attributes that are difficult, if not impossible, to achieve with conventional robots composed of rigid materials. Yet, despite recent advances, soft robots must still be tethered to hard robotic control systems and power sources. 

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