Condensed Matter and Materials Physics
- Quantum Materials
- Non-equilibrium Magnetic Materials
- Novel sp2-Bonded Materials and Related Nanostructures
- Van der Waals Heterostructures: Novel Materials and Emerging Phenomena
- Theory of Materials
- Scalable Computational Tools for Discovery and Design
- The Materials Project
- Characterization of Functional Nanomachines
- Electronic Materials
- Sub-wavelength Metamaterial Physics and Applications
- Mechanical Behavior of Advanced Materials
This program seeks to investigate the properties of strongly correlated materials by shining light onto them. Intense laser pulses have been used to restructure the free-energy landscape of these materials, and to generate rapid switching between the various forms of order deriving from the strong correlation. State of the art high harmonic generation photoemission spectroscopy and time- and spin- resolved photoemission spectroscopy systems have been developed. The future goal is to stimulate materials at selective excitations with higher intensity laser pulses to establish a mean for manipulation and control of materials properties.
M. Yi, M. Wang, A.F. Kemper, S.-K. Mo, Z. Hussain, E. Bourret-Courchesne, A. Lanzara, M. Hashimoto, D.H. Lu, Z.-X. Shen, and R.J. Birgeneau. Bandwidth and Electron Correlation-Tuned Superconductivity in Rb0.8Fe2(Se1-zSz)2. Phys. Rev. Lett. 115, 6403 (2015).
M.G. Kim, M. Wang, G.S. Tucker, P.N. Valdavia, D.L. Abernathy, S.Chi, A.D. Christianson, A.A. Axcel, T. Hong, T.W. Heitmannn, S. Ran ,P.C. Canfield, E.D. Bourret-Courchesne, A. Kreyssig, D.H. Lee, A.I. Goldman, R.J. McQueeney, and R.J. Birgeneau. Spin Dynamics near a putative quantum critical point in Cu-substituted BaFe2As2 and its relation to high temperature superconductivity. Phys. Rev. B 92, 214404 (2015).
A.K. Yadav, C.T. Nelson, S.L. Hsu, Z. Hong, J. D. Clarkson, C. M. Schlepüetz, A. R. Damodaran, P. Shafer, E. Arenholz, L.R. Dedon, D. Chen, A. Vishwanath, A. M. Minor, L.Q. Chen, J.F. Scott, L. W. Martin, and R. Ramesh. Observation of polar vortices in oxide superlattices. Nature 530, 198 (2016).
The program focuses on fundamental science of non-equilibrium magnetic materials and phenomena with emphasis on those enabled by Interfaces and Spin-Orbit-Coupling (SOC). It encompasses design, fabrication, measurement, and modeling of static and dynamic magnetic properties of thin film materials exhibiting strong spin-orbit interactions and inversion symmetry breaking due to interfaces, particularly dynamics and thermodynamics of spin accumulation, skyrmions and spin textures. The research addresses three interrelated sub-projects: i) static and quasi-static novel thin film spin structures such as skyrmions and chiral magnetic textures; ii) strong spin accumulation and consequent control of magnetization created by interfaces between ferromagnet/non-magnet with strong spin-orbit coupling; and iii) highly non-equilibrium magnetic states produced in these heterostructures and studied through electron, optical and x-ray pump/probe techniques at time scales ranging from nsec to fsec. Through strategic choice of materials and utilizing a collective expertise in growth, magnetic, electrical, optical, and thermodynamic characterization, spectromicroscopy, and theoretical modeling, the NEMM team aims to control the strength of the critical underlying, sometimes competing, interactions (spin-orbit, exchange, single ion anisotropy, Dzyaloshinskii-Moriya, Coulomb, disorder) within and between dissimilar materials in proximity to each other, enabling development of models for resulting magnetic states and their dynamics. Theoretical modeling will provide a basis for understanding the structure (atomic, electronic, magnetic) and dynamics (electron and spin transport, magnetization response) of these states, and will guide the exploration of the multidimensional space of new material systems.
N. Roschewsky, T. Matsumura, S. Cheema, F. Hellman, T. Kato, S. Iwata, S. Salahuddin. Spin-orbit torques in ferrimagnetic GdFeCo alloys. Appl. Phys. Lett. 109, 112403 (2016).
M. Charilaou, C. Bordel, P.-E. Berche, B. B. Maranville, P. Fischer, F. Hellman. Magnetic properties of ultrathin discontinuous Co/Pt multilayers: comparison with short-range ordered and isotropic CoPt3 films. Phys Rev B 93 224408 (2016).
X. Shi, P. Fischer, V. Neu, D. Elefant, J. C.T. Lee, D. A. Shapiro, M. Farmand, T. Tyliszczak, H.-W. Shiu, S. Marchesini, S. Roy, S. D. Kevan. Soft x-ray ptychography studies of nanoscale magnetic and structural correlations in thin SmCo5 films. Appl Phys Lett 108, 094103 (2016).
The sp2 program investigates, both theoretically and experimentally, sp2-bonded structures which include carbon nanotubes, graphene, nanowires, onions, fullerenes, nanocrystals, hybrid structures, non-carbon nanomaterials (including BN), and nanococoons. Interest is in the design, synthesis, characterization, and application of sp2-bonded materials whose dimensions range from 1-100 nm. This program has three major thrusts: The first, fundamentals, focuses on theoretical predictions of new stable structures, theoretical and experimental examinations of intrinsic electronic, magnetic, and mechanical responses, transport measurements (electrical resistivity, thermal conductivity, isotope effects, Raman, photoemission spectroscopy, TEM, STM), and mechanical properties and tensile strength. The second focus is on functionalized nanosystems, where two or more distinct nanostructures are brought together and allowed to interact. Here, focus is on methodologies to integrate nanosystems comprised of graphene, hBN, nanotubes, and other nanoparticles interfaced to each other or to complementary nanostructures and materials. The third and final thrust is on growth of nanostructures. Novel synthesis methods are explored for non-equilibrium growth of sp2-based and other nanoscale materials. This program also seeks to develop specialized instrumentation for synthesis, characterization, and applications.
S. Onishi, M. Moreno Ugeda, Y. Zhang, Y. Chen, C, Ojeda-Aristizabal, H. Ryu, S.-K. Mo, Z. Hussain, Z.-X. Shen, M. Crommie, and A. Zettl. Selenium capped monolayer NbSe2 for two-dimensional superconductivity studies. Physica Status Solidi B (2016).
J. Lee, D. Wong, J. Velasco Jr, J. F. Rodriguez-Nieva, S. Kahn, H.-Z. Tsai, T. Taniguchi, K. Watanabe, A. Zettl, F. Wang, L. S. Levitov, and M. F. Crommie. Imaging electrostatically confined Dirac fermions in graphene quantum dots. Nature Phys. (2016).
Y. Zhang, M. M. Ugeda, C. Jin, S.-F. Shi, A. J. Bradley, A. Martín-Recio, H. Ryu, J. Kim, S. Tang, Y. Kim, B. Zhou, C. Hwang, Y. Chen, F. Wang, M. F. Crommie, Z. Hussain, Z-X. Shen, and S.-K. Mo. Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe2 Thin Films. Nano Lett. 16, 2485 (2016).
C. Jin, J. Kim, J. Suh, Z. Shi, B. Chen, X. Fan, M. Kam, K. Watanabe, T. Taniguchi, S. Tongay, A. Zettl, J. Wu, F. Wang. Interlayer electron-phonon coupling in WSe2/hBN heterostructures. Nature Physics (2016).
The goal of this program is to understand and compute material properties and behaviors, covering a range of systems that include complex materials, nanostructures, superconductors, reduced-dimensional materials, and strongly correlated electron systems. The major objectives include studies on: superconductivity and mechanisms; excited states in novel materials and nanostructures; methodology developments; symmetry and topological phases of matter; and transport phenomena. A variety of theoretical techniques are employed, ranging from first-principles electronic structure methods and many-body perturbation theory approaches to new conceptual and computational frameworks suitable for complex materials/nanostructures and strongly interacting systems. Close collaboration with experimentalists is maintained. Equally important is the development of computational methods suitable for increasingly complex materials, reduced dimensional systems, and strongly correlated materials.
J Ma, ZF. Liu, JB Neaton, LW Wang. The energy level alignment at metal–molecule interfaces using Wannier–Koopmans method. Appl. Phys. Lett. 108, 262104 (2016).
J. I. Mustafa, S. Coh, M. L. Cohen, and S. G. Louie. Automated construction of maximally localized Wannier functions for bands with nontrivial topology. Phys. Rev. B 94, 125151 (2016).
S. Coh, D.-H. Lee, S. G. Louie, and M. L. Cohen. Proposal for a bulk material based on a monolayer FeSe on SrTiO3 high-temperature superconductor. Phys. Rev. B 93, 245138 (2016).
This is a multidisciplinary program of physical scientists, applied mathematicians, and computational scientists whose goal is to develop and implement new first-principles methods/theories to predict excited-state phenomena in materials. Advanced algorithms and many-body theory techniques are employed to compute electron excitations, optical spectra, transport properties, and other excited-state properties/processes. Methods and algorithm advances are incorporated into the BerkeleyGW package, an open-source code available freely to the community.
F Bruneval, T Rangel, S M Hamed, M Shao, C Yang, and JB Neaton. Many-body perturbation theory software for atoms, molecules, and clusters. Comput. Phys. Commun. 208, 149 (2016).
M. Y. Shao, L. Lin, C. Yang, F. Liu, F. H. Da Jornada, J. Deslippe, and S. G. Louie. Low rank approximation in G0W0 calculations. Sci China Math 59, 1593 (2016).
M. Y. Shao, F. H. da Jornada, C. Yang, J. Deslippe, and S. G. Louie. Structure Preserving Parallel Algorithms for Solving the Bethe-Salpeter Eigenvalue Problem. Linear Algebra Appl. 488, 148 (2016).
The Materials Project aims to accelerate materials discovery and education through advanced scientific computing and innovative design methods, scale those computations to cover all known inorganic compounds, and disseminate that information and design tools to the larger materials community. Specifically the Project is achieving this by:
- Providing unprecedented data and materials design tools as well as comprehensive capabilities for scientists to share their processes and results.
- Leveraging high-throughput calculations, state-of-the-art electronic structure methods as well as novel data mining algorithms for surface, defect, electronic and finite temperature property predictions for tens of thousands of materials to yield an unparalleled materials design environment.
- Demonstrating the derived data and infrastructure in the design of novel functional electronic materials: photovoltaics, thermoelectrics, transparent conductors and photocatalytic materials.
Maarten de Jong, Wei Chen, Randy Notestine, Kristin Persson, Gerbrand Ceder, Anubhav Jain, Mark Asta, and Anthony Gamst. A Statistical Learning Framework for Materials Science: Application to Elastic Moduli of k-nary Inorganic Polycrystalline Compounds. Sci Rep. 6:34256 (2016).
Tran, R.; Xu, Z.; Radhakrishnan, B.; Winston, D.; Sun, W.; Persson, K. A.; Ong, S. P. Surface energies of elemental crystals. Sci. Data, 3:160080 (2016).
Jain, A., Shin, Y. & Persson, K. A. Computational predictions of energy materials using density functional theory. Nat. Rev. Mater. 1, 15004 (2016).
The goal of this program is to understand the fundamental principles of nanomachine systems and to apply those principles toward the creation of new molecule-based nanomachines capable of converting energy into directed mechanical action at the nanoscale. The program seeks to understand the microscopic mechanisms underlying nanomechanical energy conversion in both synthetic and naturally occurring nanomachines that operate in different dissipative environments. Establishing new techniques to achieve controlled "bottom-up" fabrication of molecular nanostructures at surfaces is an important component of this program.
P. Rodriguez-Aliaga, L. Ramirez, F. Kim, C. Bustamante, and A. Martin. Substrate-translocating loops regulate mechanochemical coupling and power production in AAA+ protease ClpXP. Substrate-translocating loops regulate mechanochemical coupling and power production in AAA+ protease ClpXP. Nat. Struct. Mol. Biol. 23 (2016).
A. Riss, A. Perez Paz, S. Wickenburg, H.-Z. Tsai, D.G. de Oteyza, A.J. Bradley, M.M. Ugeda, P. Gorman, H.S. Jung, M.F. Crommie, A. Rubio, and F.R. Fischer. Imaging Single-Molecule Reaction Intermediates Stabilized by Surface Dissipation and Entropy. Nat. Chem. 8, 678-683 (2016).
H.-Z. Tsai, A.A. Omrani, S. Coh, H. Oh, S. Wickenburg, Y.-W. Son, D. Wong, A. Riss, H.S. Jung, G.D. Nguyen, G.F. Rodgers, A.S. Aikawa, T. Taniguchi, K. Watanabe, A. Zettl, S.G. Louie, J. Lu, M.L. Cohen, and M.F. Crommie. Molecular self-assembly in a poorly screened environment: F4TCNQ on graphene/BN. ACS Nano 9, 12, 12168 (2015).
Electronic Material Program (EMAT) discovers and creates semiconductors of novel composition and morphology for energy applications by removing chemical and physical constraints that limit materials performance and growth. The program has three thrust areas:
- Thrust 1: Defect control in 2D semiconductors
- Thrust 2: Interface enabled band engineering
- Thurst 3: New synthesis modes for qunatum membranes
Common to these research themes is a synthetic strategy that allows to control structure and phase transitions at the nanoscale. In the case of quantum membranes, the ability to make and control free-standing 2-D semiconductors enables study of the interplay of quantum confinement and surface/interface properties with electronic structure and carrier transport at a fundamental level. Focus has been on exploring their electrical and optoelectronic properties at the ideal limit by repairing/passivating their defects. The control of materials composition via highly non-equilibrium synthesis techniques allows to tune band structures and interface properties on command. By exploiting new insights in the nanoscale control of phase transitions, one can synthesize new functional structures. As an example, single-crystalline growth of InP with user-defined shapes and geometry, from a few nm to 10’s of μm in lateral dimensions, on amorphous substrates is demonstrated for the first time.
Chen, K.; Kapadia, R.; Harker, A.; Desai, S.; Kang, J. S.; Chuang, S.; Tosun, M.; Sutter-Fella, C. M.; Tsang, M.; Zheng, Y.; Kiriya, D.; Hazra, J.; Madhvapathy, S. R.; Hettick, M.; Chen, Y.-Z.; Mastandrea, J.; Amani, M.; Cabrini, S.; Chueh, Y.-L.; Ager, J. W.; Chrzan, D. C.; Javey, A. Direct growth of single-crystalline III-V semiconductors on amorphous substrates. Nat. Comm. 7, 10502 (2016).
Jaquez, M.; Yu, K. M.; Ting, M.; Hettick, M.; Sanchez-Royo, J. F.l; Welna, M.; Javey, A.; Dubon, O. D.; Walukiewicz, W. Growth and characterization of ZnO1−xSx highly mismatched alloys over the entire composition. J. Appl. Phys. 118, 215702 (2015).
Amani, M.; Lien, D.-H.; Kiriya, D.; Xiao, J.; Azcatal, A.; Noh, J.; Madhvapathy, S. R.; Addou, R.; Santosh, KC; Dubey, M.; Cho, K.; Wallace, R. M.; Lee, S.-C.; He, J.-H.; Ager, J. W.; Zhang, X.; Yablonovitch, E.; Javey, A. Near-unity photoluminescence quantum yield in MoS2. Science 350, 1065-1068 (2015).
This program explores a new class of photonic materials, metamaterials, by designing artificial atoms and molecules and their interactions. It investigates the novel physics of metamaterials to uncover unprecedented materials properties beyond that of natural materials.
Ramezani, Y. Wang, E. Yablonovitch & X. Zhang. Unidirectional Perfect Absorber. IEEE Journal of Selected Topics in Quantum Electronics, 22 (2016).
K. L. Tsakmakidis, R. W. Boyd, E. Yablonovitch & X. Zhang. Large spontaneous-emission enhancements in metallic nanostructures: towards LEDs faster than lasers. Optics Express, 24, 16 (2016).
H. Ramezani, M. Dubois, Y. Wang, X. Zhang. Directional Excitation Without Breaking Reciprocity. New Journal of Physics (2016).
The attainment of strength and toughness is a vital requirement for structural materials; unfortunately, these properties are generally mutually exclusive. It is the lower strength, and hence tougher, materials that find use for most safety-critical applications where premature fracture is unacceptable. Accordingly, the development of strong, tough materials has traditionally been a compromise between hardness vs. ductility. The aim of this program is thus to seek the fundamental strategies to solve this “conflict” by defining basic scientific principles underlying the development of damage-tolerance in structural materials suitable for the strategic missions of transportation, energy conservation and creation. Our approach involves understanding the scientific origins of damage-tolerance, principally in advanced multiple-element metallic alloys, principally bulk-metallic glasses and high-entropy alloys, where the salient mechanisms involve a balance of intrinsic vs. extrinsic toughening. A second approach involves using concepts of natural hierarchical design to examine the development of biomimetic hybrid ceramics. We include 2D materials, such as graphene, in this work. Our overall hypothesis is that by identifying the salient strengthening and toughening mechanisms at multiple length-scales, and by mimicking natural structural architectures, all guided by theoretical modeling at atomistic to continuum levels, we can develop the scientific foundations for unique structural materials with unprecedented levels of damage-tolerance. In all cases, our focus is on the scientific interplay between the individual nano/micro-mechanisms that contribute to strength and toughness, that of plasticity and crack-tip shielding, noting that these phenomena can originate at very different structural length-scales.
B. Gludovatz, A. Hohenwarter, K. V. S. Thurston, H. Bei, Z. Wu, E. P. George, R. O. Ritchie. Exceptional Damage-Tolerance of a Medium-Entropy Alloy CrCoNi at Cryogenic Temperatures. Nature Communications, vol. 7, pp. 10602 (2016).
H. Bai, F. Walsh, B. Gludovatz, B. Delattre, C. Huang, Y. Chen, A. P. Tomsia, R. O. Ritchie. Bioinspired Hydroxyapatite/Poly(Methyl Methacrylate) Composite with Nacre-Mimetic Architecture by a Bidirectional Freezing Method. Advanced Materials, vol. 28 (1), pp. 50-56 (2016).
H. Bai, Y. Chen, B. Delattre, A. P. Tomsia, R. O. Ritchie. Bioinspired Large-Scale Aligned Porous Materials Assembled with Dual Temperature Gradients. Science Advances, vol. 1 (11), pp. e1500849 (2015).