Charge-stripe crystal phase in an insulating cuprate

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• High-temperature superconductivity in cuprates originates from doping antiferromagnetic Mott insulators.
• Doping induces electronic liquid-crystal phases, with a predicted insulating charge-stripe phase yet to be observed.

Purpose of the Study:

• To experimentally realize and characterize the predicted lightly doped charge-transfer insulating state in cuprates.
• To investigate the microscopic origins of electronic inhomogeneity in high-temperature superconductors.

Main Methods:

• Utilized surface annealing to expand the doping range in Bi-based cuprates (Bi2Sr2CaCu2O8+x).
• Employed spectroscopic imaging scanning tunneling microscopy to probe the electronic state.

Main Results:

• Successfully realized the lightly doped charge-transfer insulating state with a ~1 eV charge transfer gap.
• Provided strong evidence for unidirectional charge-stripe order with a 4a0 period.
• Observed the charge-stripe phase formation preceding the pseudogap and Fermi surface development.

Conclusions:

• The experimental realization of the charge-stripe crystal phase provides crucial insights into cuprate electronic inhomogeneity.
• This finding advances the understanding of the complex phase diagram of high-temperature superconductors.