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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Subgap collective tunneling and its staircase structure in charge density waves
Yu I Latyshev1, P Monceau, S Brazovskii
1IRE RAS, Mokhovaya 11-7, 101999 Moscow, Russia.
Physical Review Letters
|April 12, 2006
Summary
Charge density waves (CDWs) in NbSe3 and TaS3 exhibit universal tunneling spectra below the electronic gap. This reveals CDW vortices entering junctions and tunneling via phase slips between chains.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Charge density waves (CDWs) are prevalent in low-dimensional conductors like NbSe3 and TaS3.
- Understanding CDW transport mechanisms is crucial for novel electronic devices.
- Nanoscale devices offer unique platforms to probe quantum phenomena in CDWs.
Purpose of the Study:
- To investigate the tunneling spectra of charge density waves (CDWs) in NbSe3 and TaS3.
- To elucidate the underlying mechanisms of subgap tunneling in these materials.
- To explore the role of CDW vortices and phase coherence in transport.
Main Methods:
- Fabrication of nanoscale mesa devices for NbSe3 and TaS3.
- Measurement of current-voltage (I-V) characteristics and tunneling spectra.
- Analysis of temperature dependencies and scaling of spectral features.
Main Results:
- Universal subgap tunneling spectra observed below the electronic CDW gap (2Delta).
- A consistent threshold voltage (Vt ≈ 0.2Delta) and staircase fine structure in NbSe3.
- Coincident scaling of fine structures and temperature dependencies (Vt(T), Delta(T)) with transition temperatures (Tp).
Conclusions:
- The results provide evidence for sequential entry of CDW vortices into the junction.
- Tunneling current is concentrated in the cores of these CDW vortices.
- Subgap tunneling occurs via coherent phase slips across neighboring chains, highlighting the phase channel mechanism.
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