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93Nb NMR spin echo spectroscopy in single crystal NbSe3
1Department of Physics & Astronomy, UCLA, Los Angeles, California 90095-1547, USA.
Physical Review Letters
|October 15, 2008
Summary
We observed electric field induced phase displacements of charge density waves (CDW) in NbSe3 crystals. Results align with elastic depinning models, showing reversible CDW polarization near the threshold electric field.
Area of Science:
- Condensed Matter Physics
- Solid State Physics
- Materials Science
Background:
- Charge density waves (CDW) are fundamental condensed matter phenomena.
- Understanding CDW behavior under external fields is crucial for electronic applications.
- Niobium triselenide (NbSe3) is a well-studied quasi-one-dimensional conductor exhibiting CDW properties.
Purpose of the Study:
- To investigate electric field induced phase displacements of CDW in NbSe3.
- To characterize CDW polarization dynamics near the threshold electric field (ET).
- To compare experimental findings with theoretical elastic depinning models.
Main Methods:
- Utilized 93Nb Nuclear Magnetic Resonance (NMR) spin-echo spectroscopy.
- Applied unipolar and bipolar electrical pulses to a single crystal of NbSe3.
- Measured CDW polarization as a function of applied electric field strength.
Main Results:
- Observed linear and reversible CDW polarizations up to 0.96 ET.
- Found a broad distribution of CDW phase angles (up to ~60 degrees) near the threshold.
- No evidence of polarizations exceeding a CDW wavelength or diverging near ET was found.
Conclusions:
- The observed CDW polarization behavior is consistent with elastic depinning models.
- The critical regime, predicted for large systems, was not observable in this study.
- Results provide insights into the fundamental mechanisms governing CDW dynamics in response to electric fields.
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