Materials Day 2017

Professor Richard Averitt, University of California San Diego

Terahertz Quantum Metamaterials

Abstract: Electromagnetic metamaterials are typically comprised of subwavelength metal or dielectric resonators that, when fashioned as two or three-dimensional composites, result in novel optical and photonic functionalities. Importantly, the enhanced local electric and magnetic fields of these resonators are accessible leading to strong interactions upon integration with quantum materials. Ultimately, we seek to create emergent photonic composites where the whole is more than the sum of the parts. The possibilities are nearly endless with a host of quantum materials ranging from semiconductors to transition metal oxides to superconductors offering unique possibilities. This is especially true at terahertz frequencies where the electrodynamic response of quantum materials often manifest in dramatic fashion. In this talk, we will focus on terahertz quantum metamaterials (TQMs) highlighting recent examples and emphasizing that TQMs offer a two-way street to both create technologically relevant composites and to investigate fundamental condensed matter physics under extreme conditions.

About: Professor Richard Averitt is a Professor in the Department of Physics at the University of California San Diego. He served as an Associate Professor at Boston University until 2014, and as an adjunct faculty member at Boston University through 2016. His research interests include ultrafast spectroscopy of complex matter which includes correlated electron materials,metamaterials, and plasmonics.

Professor Seth Bank, University of Texas, Austin

Seamless Integration of Metals, Dielectrics, and III-V Semiconductors for Advanced Nanophotonic Devices

Abstract: We review our progress towards the seamless epitaxial integration of III-V emitters/absorbers with crystalline plasmonic materials (metals, semimetals, and doped semiconductors), as well as patterned high-contrast dielectric structures for active plasmonic, metamaterial, and metasurface applications. We show that a variety of low-loss plasmonic and dielectric materials can be integrated into close proximity with high-efficiency III-V emitters, without degradation to their optical quality.
sethbankAbout: Seth R. Bank received the B.S. from UIUC and the M.S. and Ph.D. degrees from Stanford University. After a post-doc at UCSB he joined the University of Texas at Austin, where he is currently an Associate Professor of ECE and holds a Temple Foundation Endowed Faculty Fellowship. His research centers around the growth and application of novel heterostructures and nanocomposites to electronic/photonic devices. He has coauthored over 250 papers and presentations and has received a PECASE, NSF CAREER, AFOSR YIP, ONR YIP, DARPA YFA, Young Scientist Award from ISCS, Young Investigator Award from NAMBE, and his students have received several best paper awards.

Professor Dmitri Basov, Columbia University

High-mobility electron liquid in graphene: insights by infrared nano-imaging of plasmonic waves

Abstract: Optical spectroscopies are an invaluable resource for exploring new physic of new quantum materials. Surface plasmon polaritons and other forms of hybrid light-matter polaritons provide new opportunities for advancing this line of inquiry. In particular, polaritonic images obtained with modern nano-infrared tools grant us access into regions of the dispersion relations of various excitations beyond what is attainable with conventional optics. I will discuss this emerging direction of research with two examples from graphene physics: i) ultrafast dynamics of hot photo-excited electrons [2]; and ii) ballistic electronic transport at low temperatures [3].

About: Dmitri N. Basov (PhD 1991) is a Higgins professor in the Department of Physics at Columbia University. He has served as a professor (1997-2016) and Chair (2010-2015) of Physics, University of California San Diego. His research interests include: physics of quantum materials, superconductivity, two-dimensional materials, infrared nano-optics. Professor Basov has also received many prizes and awards, including a Sloan Fellowship (1999), the Genzel Prize (2014), the Humboldt research award (2009), Frank Isakson Prize, American Physical Society (2012), and Moore Investigator (2014).

Citations
[1] D.N. Basov, M.M. Fogler and F. J. Garcia de Abajo “Polaritons in van der Waals materials”, Science 354, 195 (2016).

[2] G. X. Ni, L. Wang, M. D. Goldflam, M. Wagner, Z. Fei, A. S. McLeod, M. K. Liu, F.Keilmann, B. Özyilmaz, A. H. Castro Neto, J. Hone, M. M. Fogler and D. N. Basov Nature Photonics 10, 244 (2016)

[3] G. X. Ni, A. S. McLeod, L. Xiong et al. [in preparation].

Dr. Hou-Tong Chen, Los Alamos National Laboratory
Hybrid Metasurfaces – Functionalities Arising From Enhanced Light-Matter Interactions

Abstract: Two-dimensional metamaterials – metasurfaces – offer tremendous opportunities in realizing exotic optical phenomena and functionalities. Through tailoring the resonant response of basic building blocks as well as their mutual interactions, they enable effective control of amplitude, phase, and polarization state of optical reflection, transmission, absorption and emission, as well as wavefront shaping and beam forming. By integrating functional materials such as semiconductors and graphene at critical regions of the resonators, hybrid metasurfaces allow enhanced light-matter interactions and accomplish dynamic switching, active tuning, and enhanced nonlinearity. In this talk I will present the augmented metasurface functionalities through both structural design and materials integration, showing the promising potential of metasurfaces toward real-world applications.

About: Hou-Tong Chen received BS and MS degrees from University of Science and Technology of China in 1997 and 2000, and a Ph.D. degree from Rensselaer Polytechnic Institute in 2004, all in physics. He is currently a Technical Staff Member in the Center for Integrated Nanotechnologies, Los Alamos National Laboratory. His research interests include metamaterials and metasurfaces, terahertz science and technology, ultrafast nanophotonics, and near-field microscopy. He has published over 70 journal papers and delivered nearly 100 invited technical presentations in conferences and accredited research institutions. He is a Topical Editor of Optics Letters (since 2017), and the conference chair of the 8th Optical Terahertz Science and Technology (OTST 2019) to be held at Santa Fe, USA (2019). He won LANL Fellows’ Prize for Outstanding Research (2015), and is a Fellow of American Physical Society (2015).

Professor Daniel M. Mittleman, Brown University

Terahertz Metasurface Slab Waveguide

Abstract: We describe experimental measurements and simulations of a switchable THz metasurface device. We characterize the switching using terahertz ellipsometry, and extract parameters which enable us to model the device in a slab waveguide geometry. In this configuration, with the extended interaction path between the propagating mode and the meta-elements, the device exhibits giant phase modulation of the TE1 waveguide mode. Simulations predict that a 2π phase shift can be realized in an interaction length of less than one millimeter, for a range of frequencies near the in-plane resonance. This device offers new possibilities for phase modulation and beam steering.

About: Dr. Mittleman received his B.S. in physics from the Massachusetts Institute of Technology in 1988, and his M.S. in 1990 and Ph.D. in 1994, both in physics from the University of California, Berkeley , under the direction of Dr. Charles Shank . He then joined AT&T Bell Laboratories as a post-doctoral member of the technical staff, working first for Dr. Richard Freeman on a terawatt laser system, and then for Dr. Martin Nuss on terahertz spectroscopy and imaging. Dr. Mittleman joined the ECE Department at Rice University in September 1996. In 2015, he moved to the School of Engineering at Brown University . His research interests involve the science and technology of terahertz radiation. He is a Fellow of the OSA, the APS, and the IEEE, and is currently serving a three-year term as Chair of the International Society for Infrared Millimeter and Terahertz Waves.

Professor Willie Padilla, Duke University

All-Dielectric Metamaterials as a Platform for Fundamental and Applied Science

Abstract: We demonstrate an all-dielectric metamaterial system based on a square array of cylindrical resonators. The metasurface architecture supports two dipole-active eigenmodes of opposite symmetry that may be tuned through modification of the geometry, or dynamically with external stimuli. Further, the 2D crystallographic space group and filling fraction may be modified to alter neighbor interactions of each mode, thus tuning their radiative loss rates independently. This versatile system is useful for exploration of a host of different classes of electromagnetic materials, and we present a few computational and experimental results.

About: Willie Padilla is a Professor in the Department of Electrical and Computer Engineering at Duke University. Willie received MS and PhD degrees in Physics from the University of California San Diego and was awarded a Director’s Postdoctoral Fellowship from Los Alamos National Laboratory. Dr. Padilla begin his Professorship in 2006, was promoted to Full Professor in 2013, and heads a group working in the area of artificially structured systems including active metamaterials with a focus on computational imaging, spectroscopy and energy. Professor Padilla has more than 180 peer-reviewed journal article, two book chapters and six issued patents. In 2007 he was awarded a Young Investigator Award from the Office of Naval Research and Presidential Early Career Award for Scientists and Engineers (PECASE) in 2011. In 2012 he was elected a Fellow of the Optical Society of America and a Kavli Frontiers of Science Fellow in 2013.

Professor David R. Smith, Duke University
Photonic Metasurfaces for Wave Front Shaping and Enhancement of Optical Processes

Abstract: Metasurfaces—planar arrays consisting of discrete, scattering elements—have revolutionized the design of diffractive and holographic apertures across the electromagnetic spectrum. The metasurface concept has led to new architectures for reconfigurable antennas and apertures, relevant for sensing and imaging applications, and provide substantial performance benefits. The metamaterial elements used in metasurfaces can further be used to enhance optical processes in integrated materials, so that hybrid metasurfaces can be explored for light generation, detection or modulation. Here we review some of the basic aspects of metasurfaces, and highlight our recent work on film-coupled nanoparticle metasurfaces, which combine plasmonic interactions with other light management functions.

About: Dr. David R. Smith is the James B. Duke Distinguished Professor of the Electrical and Computer Engineering Department at Duke University, where he also serves as Director for the Center for Metamaterial and Integrated Plasmonics. Dr. Smith is also the Founding Director of the Metamaterials Commercialization Center at Intellectual Ventures in Bellevue, Washington. Dr. Smith received his Ph.D. in 1994 in Physics from UCSD. Dr. Smith’s research interests include the theory, simulation and characterization of unique electromagnetic structures, including photonic crystals, metamaterials and plasmonic nanostructures. Smith and his colleagues demonstrated the first left-handed (or negative index) metamaterial at microwave frequencies in 2000, and also demonstrated a metamaterial “invisibility cloak” in 2006. In 2005, Dr. Smith was part of a five-member team that received the Descartes Research Prize, awarded by the European Union, for their contributions to metamaterials and other novel electromagnetic materials. In 2006, Dr. Smith was selected as one of the “Scientific American 50.” Since 2009, Dr. Smith has continually been named a “Citation Laureate” by ISI Web of Knowledge for having among the most number of highly cited papers in the field of Physics. Dr. Smith is a co-recipient of the McGroddy Prize for New Materials, awarded by the American Physical Society, for “the discovery of metamaterials” (2013). In 2016, Dr. Smith was elected to the National Academy of Inventors. Dr. Smith has recently been active in transitioning metamaterial concepts for commercialization, being a co-founder of Evolv Technology, Echodyne Corporation, Pivotal Commware, and advisor to Kymeta Corporation—all companies devoted to developing metamaterial products.

Professor Xin Zhang, Boston University
Photonic metamaterial devices enabled by microsystems

Abstract: Photonic metamaterials consisting of subwavelength “meta-atoms” have received enormous interest due to their extraordinary and unprecedented electromagnetic properties. Particularly, the effective permittivity and permeability can be tailored and reconfigured to construct metamaterial devices by modulating or actuating the constituting meta-atoms. In the course of the development of metamaterials, microsystems pave the way for the emergence of functional photonic devices across the electromagnetic spectrum. In this talk, I will present research on MEMS-enabled metamaterial devices, from the fundamental physics to their applications to bridge the terahertz gap. Multifunctional terahertz devices including metamaterial enhanced biological/chemical sensors, detectors, spatial light and phase modulators, and perfect absorbers, will be introduced.

About: Xin Zhang a Professor with the Department of Mechanical Engineering, the Division of Materials Science and Engineering, and the Photonics Center at Boston University. Her research interests include the fundamental and applied aspects of micro/nanoelectromechanical systems, understand and exploit interesting characteristics of physics, materials, mechanics, and manufacturing technologies with forward-looking engineering efforts and practical applications ranging from energy to health care to homeland security. She is a fellow of the AAAS, AIMBE, ASME, IEEE, and OSA. In 2016, she was a recipient of the IEEE Sensors Council Technical Achievement Award (advanced career) for distinguished contributions to micro/nanoelectromechanical systems.

Professor Xiaoyu (Rayne) Zheng, Virginia Tech

Printing with Light: Ultralight, Hierarchical Architected Metamaterials

Abstract: Few solid materials exist considerably lighter than water. To decrease the density beyond this point, materials must have a porosity, which generally comes at the cost of a disproportional degradation of other desirable properties. For example, graphene aerogels have among the lowest record densities ~1kg/m3, but their strength have been degraded to tens to hundreds of Pascal (<10-8 of that of graphene). The attainment of low density has come with a price — significant reduction of mechanical properties.

3D architected metamaterials are among the lightest manmade materials created to date yet with exceptional strength and stiffness. These materials are capable of holding more than 160,000 times of their own weight while being as light as a carbon aerogel. Their performance is attributed to the hierarchical layout of structural 3D architectures from nanometers to tens of centimeters and above. I will discuss a suite of scalable additive micro- and nanoscale additive manufacturing technologies that have been developed in our group to enable fast manufacture of these architected materials in polymer, metals, ceramics and nanocomposites. Attention is focused on the exceptional mechanical performance of these micro and nanolattices, including their ultra-high strength, damage tolerance, and stiffness, and examine their potential for multifunctional applications beyond mechanics. The introduction of hierarchical 3D architectures from tens of nanometers to tens of centimeters and above has been transforming our ability to tailor metamaterial properties that break the existing scaling laws between density, strength and toughness in materials.

About: Xiaoyu (Rayne) Zheng has been an Assistant Professor of Mechanical Engineering and directs the Advanced Manufacturing and Metamaterials Laboratory at Virginia Tech since December 2015. He holds an affiliate position at the Macromolecules and Innovation Institute and the Department of Materials Science and Engineering at Virginia Tech. His research interests includes using principles of optics and mechanics to develop scalable, high precision additive manufacturing techniques, metamaterials and their multi-functional applications in material design, mechanics, energy storage and transductions. Prior to joining Virginia Tech, from 2011 to 2015, he had been a Member of Technical Staff and Principle Investigator at DOE Lawrence Livermore National Laboratory, California, where he worked on high volume additive manufacturing initiatives and materials with controlled micro-architectures (DARPA MCMA). He received his Ph.D. degree in Mechanical Engineering from Boston University in 2011 with the Outstanding Dissertation Award. He and his team had developed the world’s lightest materials capable of holding more than 160,000 of their own weight with a mass density as light as aerogels. Zheng has published over 40 journal articles, proceeding papers and book chapters. His work on Micro/nano 3D printing and architected metamaterials has been selected as top 10 innovations of 2015 by MIT Technology Review. He received ICTAS Junior Faculty Award, Inventor’s Award, Director’s Publication Excellence Award at Lawrence Livermore National Laboratory. His work has been widely reported by R&D Magazine, Materials Today, Nano Today, MRS Bulletin, American Physics Society etc.