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Ultrafast electronic state conversion at room temperature utilizing hidden state in cuprate ladder system.
R Fukaya1,2, Y Okimoto2, M Kunitomo2
1CREST, JST, Kawaguchi, Saitama 332-0012, Japan.
Nature Communications
|October 21, 2015
Summary
Scientists achieved ultrafast control over material properties using light. They demonstrated a novel method to switch between metallic and insulating states in a superconductor by manipulating carrier coherence on femtosecond timescales.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Ultrafast Spectroscopy
Background:
- Achieving photo-control of material properties on femtosecond (10^-15 s) and picosecond (10^-12 s) timescales at room temperature is a significant challenge.
- Understanding and manipulating electronic states in complex materials like superconductors is crucial for technological advancements.
Purpose of the Study:
- To demonstrate ultrafast photo-induced switching between metallic and insulating states in a two-leg ladder superconductor.
- To investigate the emergence of a hidden insulating state by tuning carrier coherence.
- To explore the potential of controlling electronic states on ultrafast timescales at room temperature.
Main Methods:
- Utilized femtosecond time-resolved reflection spectroscopy to probe material dynamics.
- Employed trains of ultrashort laser pulses to precisely control carrier coherence.
- Conducted theoretical calculations to explain the observed experimental phenomena.
Main Results:
- Demonstrated a unique ultrafast conversion between metallic and insulating states in Sr(14-x)Ca(x)Cu24O41.
- Observed the emergence of a hidden insulating state by tuning carrier coherence over a wide temperature range.
- Showed that injected holes reduce coherence among inherent hole pairs, suppressing conductivity—an effect contrary to conventional photocarrier-doping.
Conclusions:
- Control of hole-pair coherence is a viable strategy for tuning electronic states on ultrafast timescales at room temperature.
- The findings offer a new pathway for manipulating material properties with light for advanced applications.
- The study provides a theoretical framework explaining the observed photocarrier dynamics in superconductors.
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