Table of contents

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Beyond particle physics p1139


Topological semimetals give access to new quantum phenomena — for example, massless fermions have not been observed as elementary particles, yet they can be realized in the form of quasiparticles in these materials — and could allow the development of robust quantum devices.



Weyl semimetals, Fermi arcs and chiral anomalies pp1140 - 1144

Shuang Jia, Su-Yang Xu & M. Zahid Hasan


Physicists have discovered a new topological phase of matter, the Weyl semimetal, whose surface features a non-closed Fermi surface whereas the low-energy quasiparticles in the bulk emerge as Weyl fermions. A brief review of these developments and perspectives on the next steps forward are presented.

Topological semimetals pp1145 - 1148

A. A. Burkov


Topological semimetals and metals have emerged as a new frontier in the field of quantum materials. Novel macroscopic quantum phenomena they exhibit are not only of fundamental interest, but may hold some potential for technological applications.


News and Views

Weyl semimetals: Magnetically induced pp1149 - 1150

Claudia Felser & Binghai Yan


The half-Heusler GdPtBi is found to show transport and calorimetric signatures of the existence of Weyl fermions under the application of a magnetic field. The half-Heusler alloys form a big family of tunable compounds that may substantially enlarge the number of Weyl semimetals known.

See also: Letter by Hirschberger et al.

Amorphous solids: Rayleigh scattering revisited pp1150 - 1151

Jeppe C. Dyre


Scaling of the phonon damping with the wavevector in glasses is found to be different from the traditionally assumed Rayleigh scattering, and related to surprising, long-range correlations in the local elasticity matrix.

See also: Article by Gelin et al.

Colloidal crystals: Stresses come to light pp1151 - 1152

Mark Bowick & Paul Chaikin


Confocal microscopy and computational analysis, now used for measuring microscale stresses in colloidal crystals, could be developed for investigation of amorphous materials, crystal melting, and mechanical properties of tissues.

See also: Letter by Lin et al.

Materials synthesis: Two-dimensional gallium nitride pp1153 - 1154

Nikhil A. Koratkar


Graphene is used as a capping sheet to synthesize 2D gallium nitride by means of migration-enhanced encapsulation growth. This technique may allow the stabilization of 2D materials that are not amenable to synthesis by traditional methods.

See also: Letter by Al Balushi et al.

Material witness: Searching the web p1154

Philip Ball




Spectroscopic evidence for a type II Weyl semimetallic state in MoTe2 pp1155 - 1160

Lunan Huang, Timothy M. McCormick, Masayuki Ochi, Zhiying Zhao, Michi-To Suzuki, Ryotaro Arita, Yun Wu, Daixiang Mou, Huibo Cao, Jiaqiang Yan, Nandini Trivedi & Adam Kaminski


MoTe2 is reported to host type II topological Weyl semimetal states. Two sets of Weyl points exist at different energies above the Fermi energy. Fermi arcs that form closed loops and are unique to type II Weyl semimetals are also found.

The chiral anomaly and thermopower of Weyl fermions in the half-Heusler GdPtBi pp1161 - 1165

Max Hirschberger, Satya Kushwaha, Zhijun Wang, Quinn Gibson, Sihang Liang, Carina A. Belvin, B. A. Bernevig, R. J. Cava & N. P. Ong


The half-Heusler GdPtBi is reported to exhibit negative longitudinal magnetoresistance. This is attributed to the chiral anomaly due to the formation of Weyl nodes with an applied magnetic field. The anomaly is also found to suppress the thermopower.

See also: News and Views by Felser & Yan

Two-dimensional gallium nitride realized via graphene encapsulation pp1166 - 1171

Zakaria Y. Al Balushi, Ke Wang, Ram Krishna Ghosh, Rafael A. Vilá, Sarah M. Eichfeld, Joshua D. Caldwell, Xiaoye Qin, Yu-Chuan Lin, Paul A. DeSario, Greg Stone, Shruti Subramanian, Dennis F. Paul, Robert M. Wallace, Suman Datta, Joan M. Redwing & Joshua A. Robinson


A method to synthesize 2D layers of gallium nitride on SiC is reported. Epitaxial graphene preliminarily grown on SiC allows intercalation of gallium atoms on the SiC substrate and stabilizes the 2D gallium nitride islands formed by ammonolysis.

See also: News and Views by Koratkar

Measuring nonlinear stresses generated by defects in 3D colloidal crystals pp1172 - 1176

Neil Y. C. Lin, Matthew Bierbaum, Peter Schall, James P. Sethna & Itai Cohen


Nonlinear stresses surrounding defect cores in three-dimensional colloidal crystals are experimentally determined at the single-particle level.

See also: News and Views by Bowick & Chaikin



Anomalous phonon scattering and elastic correlations in amorphous solids pp1177 - 1181

Simon Gelin, Hajime Tanaka & Anaël Lemaître


Studies of the phonon damping mechanism in glasses reveal scaling with the wavevector k which is different from the traditionally assumed Rayleigh scattering. These findings are related to long-range correlations in the local stress.

See also: News and Views by Dyre

Electrochemical stiffness in lithium-ion batteries pp1182 - 1187

Hadi Tavassol, Elizabeth M. C. Jones, Nancy R. Sottos & Andrew A. Gewirth


Electrochemically induced stresses in battery electrodes leading to performance degradation are still poorly understood. In situ measurements show that stress scales proportionally with lithium intercalation rate and strain with capacity.

Anisotropic phase segregation and migration of Pt in nanocrystals en route to nanoframe catalysts pp1188 - 1194

Zhiqiang Niu, Nigel Becknell, Yi Yu, Dohyung Kim, Chen Chen, Nikolay Kornienko, Gabor A. Somorjai & Peidong Yang


Anisotropic phase segregation and migration of Pt in nanocrystals is important in designing enhanced catalysts. Insight into the mechanism of Pt–Ni rhombic dodecahedra growth may provide a way to produce nanocatalysts with improved performance.

The nanocomposite nature of bone drives its strength and damage resistance pp1195 - 1202

Ottman A. Tertuliano & Julia R. Greer


Nanomechanical experiments on samples of the ordered and disordered phases of trabecular bone show a transition from plastic deformation to brittle failure.

Detection and imaging of quorum sensing in Pseudomonas aeruginosa biofilm communities by surface-enhanced resonance Raman scattering pp1203 - 1211

Gustavo Bodelón, Verónica Montes-García, Vanesa López-Puente, Eric H. Hill, Cyrille Hamon, Marta N. Sanz-Ortiz, Sergio Rodal-Cedeira, Celina Costas, Sirin Celiksoy, Ignacio Pérez-Juste, Leonardo Scarabelli, Andrea La Porta, Jorge Pérez-Juste, Isabel Pastoriza-Santos & Luis M. Liz-Marzán


Nanostructured plasmonic substrates are used for in situ, label-free detection, by surface-enhanced resonance Raman scattering spectroscopy, of quorum sensing in growing Pseudomonas aeruginosa biofilms.

Mechanism of hard-nanomaterial clearance by the liver pp1212 - 1221

Kim M. Tsoi, Sonya A. MacParland, Xue-Zhong Ma, Vinzent N. Spetzler, Juan Echeverri, Ben Ouyang, Saleh M. Fadel, Edward A. Sykes, Nicolas Goldaracena, Johann M. Kaths, John B. Conneely, Benjamin A. Alman, Markus Selzner, Mario A. Ostrowski, Oyedele A. Adeyi, Anton Zilman, Ian D. McGilvray & Warren C. W. Chan


The blood clearance mechanism, by the liver, of administered hard nanomaterials is reported in relation to blood flow dynamics, organ microarchitecture and cellular phenotype.