Intrinsic Heavy Wigner Crystal Forged by Transferred 4f Electrons.

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Electron Correlation

Background:

• Realizing robust Wigner crystals and achieving angstrom-scale imaging are significant challenges in quantum matter research.
• 4f electrons are known for their localized and correlated nature, suggesting potential for novel quantum states.

Purpose of the Study:

• To develop a novel strategy for creating and imaging intrinsic electron solids.
• To investigate the properties of a Wigner crystal formed by 4f electrons.
• To explore the potential of 4f systems as a platform for studying 2D many-body correlations.

Main Methods:

• Charge-transfer-crystallization strategy was employed to synthesize the electron solid.
• Q-plus atomic force microscopy (Q-plus AFM) and Kelvin probe force microscopy (KPFM) were used for direct imaging.
• Imaging techniques allowed for determination of sub-unit-cell localization and electrostatic influence of electrons.

Main Results:

• An intrinsic heavy Wigner crystal composed of 4f electrons was successfully realized.
• The Wigner crystal exhibited record-high electron density (2.02×10^13/cm^-2) and a melting temperature above 60 K.
• Direct imaging confirmed sub-unit-cell localization, and collective tunneling was observed, highlighting quantum properties.

Conclusions:

• The study demonstrates a novel charge-transfer-crystallization method to create heavy Wigner crystals from 4f electrons.
• The realized Wigner crystal possesses unique properties, including high density and melting temperature.
• The 4f system serves as a tunable platform for investigating 2D many-body correlations in heavy electron systems.