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Luo Y, Martin-Jimenez A, Pisarra M, Martin F, Garg M, Kern K. Imaging and controlling coherent phonon wave packets in single graphene nanoribbons. Nat Commun 2023; 14:3484. [PMID: 37311753 DOI: 10.1038/s41467-023-39239-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023] Open
Abstract
The motion of atoms is at the heart of any chemical or structural transformation in molecules and materials. Upon activation of this motion by an external source, several (usually many) vibrational modes can be coherently coupled, thus facilitating the chemical or structural phase transformation. These coherent dynamics occur on the ultrafast timescale, as revealed, e.g., by nonlocal ultrafast vibrational spectroscopic measurements in bulk molecular ensembles and solids. Tracking and controlling vibrational coherences locally at the atomic and molecular scales is, however, much more challenging and in fact has remained elusive so far. Here, we demonstrate that the vibrational coherences induced by broadband laser pulses on a single graphene nanoribbon (GNR) can be probed by femtosecond coherent anti-Stokes Raman spectroscopy (CARS) when performed in a scanning tunnelling microscope (STM). In addition to determining dephasing (~440 fs) and population decay times (~1.8 ps) of the generated phonon wave packets, we are able to track and control the corresponding quantum coherences, which we show to evolve on time scales as short as ~70 fs. We demonstrate that a two-dimensional frequency correlation spectrum unequivocally reveals the quantum couplings between different phonon modes in the GNR.
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Affiliation(s)
- Yang Luo
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
| | - Alberto Martin-Jimenez
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
| | - Michele Pisarra
- INFN-LNF, Gruppo Collegato di Cosenza, Via P. Bucci, cubo 31C, 87036, Rende (CS), Italy
| | - Fernando Martin
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nano), Faraday 9, Cantoblanco, 28049, Madrid, Spain
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Manish Garg
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
| | - Klaus Kern
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
- Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
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Liang K, Bi L, Zhu Q, Zhou H, Li S. Ultrafast Dynamics Revealed with Time-Resolved Scanning Tunneling Microscopy: A Review. ACS APPLIED OPTICAL MATERIALS 2023; 1:924-938. [PMID: 37260467 PMCID: PMC10227725 DOI: 10.1021/acsaom.2c00169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/23/2023] [Indexed: 06/02/2023]
Abstract
A scanning tunneling microscope (STM) capable of performing pump-probe spectroscopy integrates unmatched atomic-scale resolution with high temporal resolution. In recent years, the union of electronic, terahertz, or visible/near-infrared pulses with STM has contributed to our understanding of the atomic-scale processes that happen between milliseconds and attoseconds. This time-resolved STM (TR-STM) technique is evolving into an unparalleled approach for exploring the ultrafast nuclear, electronic, or spin dynamics of molecules, low-dimensional structures, and material surfaces. Here, we review the recent advancements in TR-STM; survey its application in measuring the dynamics of three distinct systems, nucleus, electron, and spin; and report the studies on these transient processes in a series of materials. Besides the discussion on state-of-the-art techniques, we also highlight several emerging research topics about the ultrafast processes in nanoscale objects where we anticipate that the TR-STM can help broaden our knowledge.
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Affiliation(s)
- Kangkai Liang
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Liya Bi
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Qingyi Zhu
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
| | - Hao Zhou
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Shaowei Li
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
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