1
|
Garg M, Martin-Jimenez A, Luo Y, Kern K. Ultrafast Photon-Induced Tunneling Microscopy. ACS NANO 2021; 15:18071-18084. [PMID: 34723474 PMCID: PMC8613903 DOI: 10.1021/acsnano.1c06716] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/26/2021] [Indexed: 05/25/2023]
Abstract
Unification of the techniques of ultrafast science and scanning tunneling microscopy (STM) has the potential of tracking electronic motion in molecules simultaneously in real space and real time. Laser pulses can couple to an STM junction either in the weak-field or in the strong-field interaction regime. The strong-field regime entails significant modification (dressing) of the tunneling barrier of the STM junction, whereas the weak-field or the photon-driven regime entails perturbative interaction. Here, we describe how photons carried in an ultrashort pulse interact with an STM junction, defining the basic fundamental framework of ultrafast photon-induced tunneling microscopy. Selective dipole coupling of electronic states by photons is shown to be controllable by adjusting the DC bias at the STM junction. An ultrafast tunneling microscopy involving photons is established. Consolidation of the technique calls for innovative approaches to detect photon-induced tunneling currents at the STM junction. We introduce and characterize here three techniques involving dispersion, polarization, and frequency modulation of the laser pulses to lock-in detect the laser-induced tunneling current. We show that photon-induced tunneling currents can simultaneously achieve angstrom scale spatial resolution and sub-femtosecond temporal resolution. Ultrafast photon-induced tunneling microscopy will be able to directly probe electron dynamics in complex molecular systems, without the need of reconstruction techniques.
Collapse
Affiliation(s)
- Manish Garg
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Alberto Martin-Jimenez
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Yang Luo
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - Klaus Kern
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany
- Institut
de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| |
Collapse
|
2
|
Zhao T, Knappenberger KL. Advances in multi-dimensional super-resolution nonlinear optical microscopy. ADVANCES IN PHYSICS: X 2021. [DOI: 10.1080/23746149.2021.1964378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Tian Zhao
- Department Of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, United States
| | - Kenneth L. Knappenberger
- Department Of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, United States
| |
Collapse
|
3
|
Lee J, Tallarida N, Rios L, Ara Apkarian V. The Raman Spectrum of a Single Molecule on an Electrochemically Etched Silver Tip. APPLIED SPECTROSCOPY 2020; 74:1414-1422. [PMID: 32705875 DOI: 10.1177/0003702820949274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We recorded the Raman spectrum of a single azobenzene thiol molecule upon picking it up from an atomically flat gold surface, using an electrochemically etched silver tip, in an ultrahigh vacuum cryogenic scanning tunneling microscope. While suppressed at the junction, the stationary spectrum appeared once the molecule was transferred to the tip, with line intensities that increased by a factor of ∼5 as the tip was retracted from 1 nm to 161 nm. The effect, and the enhanced tensorial Raman spectrum was reproduced using an explicit treatment of the electromagnetic fields to identify a cis-azobenzene thiol molecule, adsorbed on a nanometric asperity removed from the tip apex, lying in the plane normal to the tip z-axis, with enhanced incident and radiative local fields polarized in the same plane. Tips decorated with asperities break the rules and give unique insights on Raman driven by cavity modes of a plasmonic junction.
Collapse
Affiliation(s)
- Joonhee Lee
- Department of Physics, University of Nevada, Reno, NV, USA
| | - Nicholas Tallarida
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Laura Rios
- Department of Physics, California Polytechnic State University, San Luis Obispo, CA, USA
| | - V Ara Apkarian
- Department of Chemistry, University of California, Irvine, CA, USA
| |
Collapse
|
4
|
Garg M, Kern K. Attosecond coherent manipulation of electrons in tunneling microscopy. Science 2020; 367:411-415. [DOI: 10.1126/science.aaz1098] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/30/2019] [Indexed: 01/24/2023]
Affiliation(s)
- M. Garg
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - K. Kern
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
- Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| |
Collapse
|
5
|
Miwa K, Najarian AM, McCreery RL, Galperin M. Hubbard Nonequilibrium Green's Function Analysis of Photocurrent in Nitroazobenzene Molecular Junction. J Phys Chem Lett 2019; 10:1550-1557. [PMID: 30879300 DOI: 10.1021/acs.jpclett.9b00270] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a combined experimental and theoretical study of photoinduced current in molecular junctions consisting of monolayers of nitroazobenzene oligomers chemisorbed on carbon surfaces and illuminated by ultraviolet-visible light through a transparent electrode. Experimentally observed dependence of the photocurrent on light frequency, temperature, and monolayer thickness is analyzed within first-principles simulations employing the Hubbard nonequilibrium Green's function diagrammatic technique. We reproduce qualitatively correct behavior and discuss mechanisms leading to the characteristic behavior of dark and photoinduced currents in response to changes in bias, frequency of radiation, temperature, and thickness of molecular layer.
Collapse
Affiliation(s)
- Kuniyuki Miwa
- Department of Chemistry and Biochemistry , University of California San Diego , La Jolla , California 92034 , United States
| | | | | | - Michael Galperin
- Department of Chemistry and Biochemistry , University of California San Diego , La Jolla , California 92034 , United States
| |
Collapse
|
6
|
Liu S, Wolf M, Kumagai T. Plasmon-Assisted Resonant Electron Tunneling in a Scanning Tunneling Microscope Junction. PHYSICAL REVIEW LETTERS 2018; 121:226802. [PMID: 30547648 DOI: 10.1103/physrevlett.121.226802] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Indexed: 05/25/2023]
Abstract
We report plasmon-assisted resonant electron tunneling from a Ag or Au tip to field emission resonances (FERs) of a Ag(111) surface induced by cw laser excitation of a scanning tunneling microscope (STM) junction at visible wavelengths. As a hallmark of the plasmon-assisted resonant tunneling, we observe a downshift of the first peak in the FER spectra by a fixed amount equal to the incident photon energy. STM-induced luminescence measurement for the Ag and Au tip reveals the clear correlation between the laser-induced change in the FER spectra and the plasmonic properties of the junction. Our results clarify a novel resonant electron transfer mechanism in a plasmonic nanocavity.
Collapse
Affiliation(s)
- Shuyi Liu
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Martin Wolf
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Takashi Kumagai
- Department of Physical Chemistry, Fritz-Haber Institute of the Max-Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
- JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| |
Collapse
|
7
|
Meng X, Jin W, Yang H, Dadap JI, Osgood RM, Dolocan A, Sutter P, Camillone N. Two-color field enhancement at an STM junction for spatiotemporally resolved photoemission. OPTICS LETTERS 2017; 42:2651-2654. [PMID: 28957307 DOI: 10.1364/ol.42.002651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/04/2017] [Indexed: 06/07/2023]
Abstract
We report measurements and numerical simulations of ultrafast laser-excited carrier flow across a scanning tunneling microscope (STM) junction. The current from a nanoscopic tungsten tip across a ∼1 nm vacuum gap to a silver surface is driven by a two-color excitation scheme that uses an optical delay-modulation technique to extract the two-color signal from background contributions. The role of optical field enhancements in driving the current is investigated using density functional theory and full three-dimensional finite-difference time-domain computations. We find that simulated field-enhanced two-photon photoemission (2PPE) currents are in excellent agreement with the observed exponential decay of the two-color photoexcited current with increasing tip-surface separation, as well as its optical-delay dependence. The results suggest an approach to 2PPE with simultaneous subpicosecond temporal and nanometer spatial resolution.
Collapse
|
8
|
Single-molecule instant replay. Nature 2016; 539:170-171. [DOI: 10.1038/539170a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Wang H, Lu Z, Kong D, Sun J, Hymel TM, Cui Y. Electrochemical tuning of MoS2 nanoparticles on three-dimensional substrate for efficient hydrogen evolution. ACS NANO 2014; 8:5-13. [PMID: 24716529 DOI: 10.1021/nn4064538] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Molybdenum disulfide (MoS2) with the two-dimensional layered structure has been widely studied as an advanced catalyst for hydrogen evolution reaction (HER). Intercalating guest species into the van der Waals gaps of MoS2 has been demonstrated as an effective approach to tune the electronic structure and consequently improve the HER catalytic activity. In this work, by constructing nanostructured MoS2 particles with largely exposed edge sites on the three-dimensional substrate and subsequently conducting Li electrochemical intercalation and exfoliation processes, an ultrahigh HER performance with 200 mA/cm(2) cathodic current density at only 200 mV overpotential is achieved. We propose that both the high surface area nanostructure and the 2H semiconducting to 1T metallic phase transition of MoS2 are responsible for the outstanding catalytic activity. Electrochemical stability test further confirms the long-term operation of the catalyst.
Collapse
Affiliation(s)
- Haotian Wang
- Department of Applied Physics and ‡Department of Materials Science and Engineering, Stanford University , 450 Serra Mall, Stanford, California 94305, United States
| | | | | | | | | | | |
Collapse
|
10
|
Stolz A, Berthelot J, Mennemanteuil MM, Colas des Francs G, Markey L, Meunier V, Bouhelier A. Nonlinear photon-assisted tunneling transport in optical gap antennas. NANO LETTERS 2014; 14:2330-2338. [PMID: 24697629 DOI: 10.1021/nl404707t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We introduce strongly coupled optical gap antennas to interface optical radiation with current-carrying electrons at the nanoscale. The transducer relies on the nonlinear optical and electrical properties of an optical gap antenna operating in the tunneling regime. We discuss the underlying physical mechanisms controlling the conversion involving d-band electrons and demonstrate that a simple two-wire optical antenna can provide advanced optoelectronic functionalities beyond tailoring the electromagnetic response of a single emitter. Interfacing an electronic command layer with a nanoscale optical device may thus be facilitated by the optical rectennas discussed here.
Collapse
Affiliation(s)
- Arnaud Stolz
- Laboratoire Interdisciplinaire Carnot de Bourgogne CNRS-UMR 6303, Université de Bourgogne , 21078 Dijon, France
| | | | | | | | | | | | | |
Collapse
|