Attosecond coherent manipulation of electrons in tunneling microscopy

Science ◽  
2019 ◽  
Vol 367 (6476) ◽  
pp. 411-415 ◽  
Author(s):  
M. Garg ◽  
K. Kern
Keyword(s):  
Tunnel Junction ◽  
Coherent Control ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Optical Pulses ◽  
Nanoelectronic Devices ◽  
Electronic Current ◽  
And Control ◽  
Coherent Manipulation ◽  
Manipulation And Control

Nanoelectronic devices operating in the quantum regime require coherent manipulation and control over electrons at atomic length and time scales. We demonstrate coherent control over electrons in a tunnel junction of a scanning tunneling microscope by means of precise tuning of the carrier-envelope phase of two-cycle long (<6-femtosecond) optical pulses. We explore photon and field-driven tunneling, two different regimes of interaction of optical pulses with the tunnel junction, and demonstrate a transition from one regime to the other. Our results show that it is possible to induce, track, and control electronic current at atomic scales with subfemtosecond resolution, providing a route to develop petahertz coherent nanoelectronics and microscopy.

scholarly journals Mechanical single-molecule potentiometers with large switching factors from ortho-pentaphenylene foldamers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jinshi Li ◽  
Pingchuan Shen ◽  
Shijie Zhen ◽  
Chun Tang ◽  
Yiling Ye ◽  
...  
Keyword(s):  
Charge Transport ◽  
Single Molecule ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Helical Structures ◽  
Anchoring Groups ◽  
Molecular Conductance ◽  
And Control ◽  
Helical Molecules ◽  
Shed Light

AbstractMolecular potentiometers that can indicate displacement-conductance relationship, and predict and control molecular conductance are of significant importance but rarely developed. Herein, single-molecule potentiometers are designed based on ortho-pentaphenylene. The ortho-pentaphenylene derivatives with anchoring groups adopt multiple folded conformers and undergo conformational interconversion in solutions. Solvent-sensitive multiple conductance originating from different conformers is recorded by scanning tunneling microscopy break junction technique. These pseudo-elastic folded molecules can be stretched and compressed by mechanical force along with a variable conductance by up to two orders of magnitude, providing an impressively higher switching factor (114) than the reported values (ca. 1~25). The multichannel conductance governed by through-space and through-bond conducting pathways is rationalized as the charge transport mechanism for the folded ortho-pentaphenylene derivatives. These findings shed light on exploring robust single-molecule potentiometers based on helical structures, and are conducive to fundamental understanding of charge transport in higher-order helical molecules.

scholarly journals Sub-cycle Manipulation of Electrons in a Tunnel Junction with Phase-controlled Single-cycle THz Near-fields

2019 ◽  
Vol 205 ◽  
pp. 08007
Author(s):  
Katsumasa Yoshioka ◽  
Ikufumi Katayama ◽  
Yusuke Arashida ◽  
Atsuhiko Ban ◽  
Yoichi Kawada ◽  
...  
Keyword(s):  
Tunnel Junction ◽  
Phase Shifter ◽  
Electron Tunneling ◽  
Near Field ◽  
Scanning Tunneling ◽  
Electron Dynamics ◽  
Tunneling Microscopy ◽  
Single Cycle ◽  
Carrier Envelope Phase ◽  
Tunneling Dynamics

By utilizing terahertz scanning tunneling microscopy (THz-STM) with a carrier envelope phase shifter for broadband THz pulses, we could successfully control the near-field-mediated electron dynamics in a tunnel junction with sub-cycle precision. Measurements of the phase-resolved sub-cycle electron tunneling dynamics revealed an unexpected large carrier-envelope phase shift between far-field and near-field single-cycle THz waveforms.

scholarly journals Hyperfine interaction of individual atoms on a surface

Science ◽  
2018 ◽  
Vol 362 (6412) ◽  
pp. 336-339 ◽  
Author(s):  
Philip Willke ◽  
Yujeong Bae ◽  
Kai Yang ◽  
Jose L. Lado ◽  
Alejandro Ferrón ◽  
...  
Keyword(s):  
Hyperfine Interaction ◽  
Atomic Scale ◽  
Single Atom ◽  
Scanning Tunneling ◽  
Oxide Surface ◽  
Nuclear Spins ◽  
Tunneling Microscopy ◽  
Magnesium Oxide Surface ◽  
State Mixing ◽  
And Control

Taking advantage of nuclear spins for electronic structure analysis, magnetic resonance imaging, and quantum devices hinges on knowledge and control of the surrounding atomic-scale environment. We measured and manipulated the hyperfine interaction of individual iron and titanium atoms placed on a magnesium oxide surface by using spin-polarized scanning tunneling microscopy in combination with single-atom electron spin resonance. Using atom manipulation to move single atoms, we found that the hyperfine interaction strongly depended on the binding configuration of the atom. We could extract atom- and position-dependent information about the electronic ground state, the state mixing with neighboring atoms, and properties of the nuclear spin. Thus, the hyperfine spectrum becomes a powerful probe of the chemical environment of individual atoms and nanostructures.

Study of single molecules and their assemblies by scanning tunneling microscopy

2006 ◽  
Vol 78 (5) ◽  
pp. 905-933 ◽  
Author(s):  
J. G. Hou ◽  
Kedong Wang
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Density Functional ◽  
Single Molecules ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Physical Problems ◽  
The Density Functional Theory ◽  
And Control ◽  
Theoretical Simulations

The recent rapid advances in nanotechnology, especially those based on molecules, are due in large part to our newly acquired abilities to measure and manipulate individual molecules and their assemblies. Among all the approaches for the study of single molecules, scanning tunneling microscopy (STM) is unique and powerful owing to its ability to accurately probe and control single molecules. High-resolution spatial imaging combined with scanning tunneling spectroscopy (STS) helps scientists investigate and resolve many chemical and physical problems at the molecular level. In this paper, we review our recent studies of single molecules and their assemblies by combining STM experiments and theoretical simulations based on the density functional theory (DFT).

Propagation, manipulation, and control of picosecond optical pulses at 15 μm in fiber Bragg gratings

2002 ◽  
Vol 19 (11) ◽  
pp. 2742 ◽  
Author(s):  
Stefano Longhi ◽  
Marcello Marano ◽  
Paolo Laporta ◽  
Orazio Svelto ◽  
Michele Belmonte
Keyword(s):  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Optical Pulses ◽  
And Control ◽  
Manipulation And Control

Single-molecule laser nanospectroscopy with micro–electron volt energy resolution

Science ◽  
2021 ◽  
Vol 373 (6550) ◽  
pp. 95-98
Author(s):  
Hiroshi Imada ◽  
Miyabi Imai-Imada ◽  
Kuniyuki Miwa ◽  
Hidemasa Yamane ◽  
Takeshi Iwasa ◽  
...  
Keyword(s):  
Single Molecule ◽  
Stark Effect ◽  
Energy Levels ◽  
Spectroscopic Method ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Molecular Systems ◽  
Electron Volt ◽  
Exciton Coupling ◽  
And Control

Ways to characterize and control excited states at the single-molecule and atomic levels are needed to exploit excitation-triggered energy-conversion processes. Here, we present a single-molecule spectroscopic method with micro–electron volt energy and submolecular-spatial resolution using laser driving of nanocavity plasmons to induce molecular luminescence in scanning tunneling microscopy. This tunable and monochromatic nanoprobe allows state-selective characterization of the energy levels and linewidths of individual electronic and vibrational quantum states of a single molecule. Moreover, we demonstrate that the energy levels of the states can be finely tuned by using the Stark effect and plasmon-exciton coupling in the tunneling junction. Our technique and findings open a route to the creation of designed energy-converting functions by using tuned energy levels of molecular systems.

High resolution scanned tip microscopies

1988 ◽  
Vol 46 ◽  
pp. 1002-1003
Author(s):  
H.K. Wickramasinghe
Keyword(s):  
Dimensional Space ◽  
Tunneling Current ◽  
Sample Surface ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
3 Dimensional ◽  
Sample Spacing ◽  
Nobel Prize In Physics ◽  
Physical Interactions ◽  
And Control

The invention of Scanning Tunneling Microscopy (STM) which won the 1986 Nobel Prize in Physics has allowed one to image atoms on the surface of a metal or semiconductor by scanning a fine tip (whose diameter is 1000 Å in a controlled fashion very close (2Å) to the sample surface.In the STM, the tip to sample distance is controlled by measuring the tunneling current -i.e. the current that flows between the tip and sample when a voltage is applied between them- (which changes very rapidly with this distance) and using piezoelectric transducers to precisely position the tip in 3-dimensional space to lÅ accuracy. The STM responds to variations in the electron density of states of the sample surface.In this paper, we show how one can use the same piezoelectric positioning and control concepts demonstrated with the STM but rely on other physical interactions than the tunneling current to control the tip-sample spacing.

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