APS Logo

Partially-metal--coated Tips for Near-field Nanospectroscopy.

ORAL

Abstract

Here, we test the possibility of a generic design scheme for wavelength-selective tip enhancement via finite-element numerical modeling. We employ a Si-based tip with various gold coating lengths on the top, yielding a tunable near-field field strength at the tip apex. Calculations show a wavelength-dependent enhancement factor of the metal-coated tip due to the geometrical antenna resonances, which can be precisely tuned throughout a broad spectral range from visible to terahertz frequencies by adjusting the length of the metal coating. By changing the coating pattern into a chiral helical structure on an achiral tip, we also demonstrate the importance of coating-length effect in designing high-performance enantiomeric near-field scanning. Our methods and findings offer interesting perspectives for developing near-field optical probes, pushing the detection and resolution limits of tip-enhanced near-field detections and nanospectroscopies.

–

Authors

  • Yujia Zhang

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • Xinzhong Chen

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • Derek Chen

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • Ziheng Yao

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • Suheng Xu

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • Anuradha Gupta

    New Jersey Inst of Tech, Pennsylvania State University, Bard College, University of Mississippi, Drexel Univ, Collaborator, University of Dayton, Morgan State University, Louisiana State University, University of Geneva, Instituto Superior Tecnico - Lisboa, Department of Biochemistry and Molecular Biology, Rutgers University, Institute for Quantitative Biomedicine, Rutgers University, Pennsylvania State University, and University of Illinois at Urbana-Champaign, University of Illinois at Urbana-Champaign, Department of Chemical Engineering, New Jersey Institute of Technology, Department of Physics and Astronomy, Rutgers University-New Brunswick, Department of Physics, Rutgers University, Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany, Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Chemin du Musée 3, CH-1700 Fribourg, Switzerland, The MacDiarmid Institute for Advanced Materials and Nanotechnology, 1010 Auckland, New Zealand, Department of Physics, College of William & Mary, Williamsburg, VA 23187-8795, USA, New Jersey Institute of Technology, Newark, NJ, USA, University of California, Los Angeles, CA, USA, University of California, Berkeley, CA, USA, Space Research Institute of RAS, Moscow, Russia, Georgetown University, Institut Polytechnique de Paris, University of Delaware, Brookhaven National Laboratory, San Diego State University, University of Chicago, University of Illinois at Chicago, Argonne National Laboratory, Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA, University of Washington

  • M. Mumtaz Qazilbash

    Department of Physics, College of William & Mary, Williamsburg, VA 23187-8795, USA

  • Mengkun Liu

    Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA, State Univ of NY - Stony Brook, Stony Brook University