The reference section in the print version of this Letter contained the following errors: For ref. 3, the volume number should have been 4 rather than 3. For ref. 17, "15, 1289-1295" should have been "http://dx.doi.org/10.1126/science.1232009". For ref. 30, the volume number should have been 326 rather than 23. The online HTML and PDF versions of the Letter do not contain these errors. CORRIGENDUM

Materials research plays a vital role in transforming breakthrough scientific ideas into next-generation technology. Similar to the way silicon revolutionized the microelectronics industry, the proper materials can greatly impact the field of plasmonics and metamaterials. Currently, research in plasmonics and metamaterials lacks good material building blocks in order to realize useful devices. Such devices suffer from many drawbacks arising from the undesirable properties of their material building blocks, especially metals. There are many materials, other than conventional metallic components such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent conducting oxides, perovskite oxides, metal nitrides, silicides, germanides, and 2D materials such as graphene. This review provides a summary of the recent developments in the search for better plasmonic materials and an outlook of further research directions.

Plasmonics is a research area merging the fields of optics and nanoelectronics by confining light with relatively large free-space wavelength to the nanometer scale -thereby enabling a family of novel devices. Current plasmonic devices at telecommunication and optical frequencies face significant challenges due to losses encountered in the constituent plasmonic materials. These large losses seriously limit the practicality of these metals for many novel applications. This paper provides an overview of alternative plasmonic materials along with motivation for each material choice and important aspects of fabrication. A comparative study of various materials including metals, metal alloys and heavily doped semiconductors is presented. The performance of each material is evaluated based on quality factors defined for each class of plasmonic devices. Most importantly, this paper outlines an approach for realizing optimal plasmonic material properties for specific frequencies and applications, thereby providing a reference for those searching for better plasmonic materials.

The precise manipulation of a propagating wave using phase control is a fundamental building block of optical systems. The wavefront of a light beam propagating across an interface can be modified arbitrarily by introducing abrupt phase changes. We experimentally demonstrated unparalleled wavefront control in a broadband optical wavelength range from 1.0 to 1.9 micrometers. This is accomplished by using an extremely thin plasmonic layer (~λ/50) consisting of an optical nanoantenna array that provides subwavelength phase manipulation on light propagating across the interface. Anomalous light-bending phenomena, including negative angles of refraction and reflection, are observed in the operational wavelength range.

New materials are being developed that meet the requirements for nanoscale photonics.

Abstract:As alternatives to conventional metals, new plasmonic materials offer many advantages in the rapidly growing fields of plasmonics and metamaterials. These advantages include low intrinsic loss, semiconductor-based design, compatibility with standard nanofabrication processes, tunability, and others. Transparent conducting oxides such as Al:ZnO, Ga:ZnO and indium-tin-oxide (ITO) enable many high-performance metamaterial devices operating in the near-IR. Transition-metal nitrides such as TiN or ZrN can be substitutes for conventional metals in the visible frequencies. In this paper we provide the details of fabrication and characterization of these new materials and discuss their suitability for a number of metamaterial and plasmonic applications.

Abstract:The search for alternative plasmonic materials with improved optical properties, easier fabrication and integration capabilities over those of the traditional materials such as silver and gold could ultimately lead to real-life applications for plasmonics and metamaterials. In this work, we show that titanium nitride could perform as an alternative plasmonic material in the visible and near-infrared regions. We demonstrate the excitation of surface-plasmon-polaritons on titanium nitride thin films and discuss the performance of various plasmonic and metamaterial structures with titanium nitride as the plasmonic component. We also show that titanium nitride could provide performance that is comparable to that of gold for plasmonic applications and can significantly outperform gold and silver for transformation-optics and some metamaterial applications in the visible and near-infrared regions. References and links1. W. Barnes, A. Dereux, and T. Ebbesen, "Surface plasmon subwavelength optics," Nature 424, 824-830 (2003). 2. S. Lal, S. Link, and N. Halas, "Nano-optics from sensing to waveguiding," Nat. Photonics 1, 641-648 (2007). 3. D. Smith, J. Pendry, and M. Wiltshire, "Metamaterials and negative refractive index," Science 305, 788-792 (2004). 4. W. Cai and V. Shalaev, Optical Metamaterials: Fundamentals and Applications (Springer Verlag, 2009). 5. J. Pendry, D. Schurig, and D. Smith, "Controlling electromagnetic fields," Science 312, 1780-1782 (2006). 6. C. Soukoulis, S. Linden, and M. Wegener, "Physics: negative refractive index at optical wavelengths," Science 315, 47-49 (2007). 7. V. Shalaev, "Transforming light," Science 322, 384-386 (2008). 8. J. Pendry, "Negative refraction makes a perfect lens," Phys. Rev. Lett. 85, 3966-3969 (2000). 9. Z. Jacob, L. Alekseyev, and E. Narimanov, "Optical Hyperlens: Far-field imaging beyond the diffraction limit,"Opt. Express 14, 8247-8256 (2006). 10. S. Ramakrishna, J. Pendry, M. Wiltshire, and W. Stewart, "Imaging the near field," J. Mod. Opt. 50, 1419-1430 (2003). 11. W. Cai, U. Chettiar, A. Kildishev, and V. Shalaev, "Optical cloaking with metamaterials," Nat. Photonics 1, 224-227 (2007). 12. A. Kildishev and V. Shalaev, "Engineering space for light via transformation optics," Opt. Lett. 33, 43-45 (2008). 13. E. Narimanov and A. Kildishev, "Optical black hole: Broadband omnidirectional light absorber," Appl. Phys.Lett. 95, 041106 (2009). 14. N. Fang, H. Lee, C. Sun, and X. Zhang, "Sub-diffraction-limited optical imaging with a silver superlens," Science 308, 534-537 (2005). (Springer Verlag, 2007). 51. A. Hibbins, J. Sambles, and C. Lawrence, "Surface plasmon-polariton study of the optical dielectric function of titanium nitride," J. Mod. Opt. 45, 2051-2062 (1998). 52. X. Ni, Z. Liu, A. Boltasseva, and A. Kildishev, "The validation of the parallel three-dimensional solver for analysis of optical plasmonic bi-periodic multilayer nanostructures," Appl. Phys. A 100, 365-374 (2010).

A high-temperature stable broadband plasmonic absorber is designed, fabricated, and optically characterized. A broadband absorber with an average high absorption of 95% and a total thickness of 240 nm is fabricated, using a refractory plasmonic material, titanium nitride. This absorber integrates both the plasmonic resonances and the dielectric-like loss. It opens a path for the interesting applications such as solar thermophotovoltaics and optical circuits.