Direct measurement of coherent nodal and antinodal dynamics in underdoped Bi-2212
Researchers used polarization-resolved multidimensional coherent spectroscopy to measure how electronic excitations behave at different points (nodal vs. antinodal) of underdoped Bi2212 in its superconducting state. They found that nodal excitations maintain long-lived coherence and are anti-correlated with electronic states near 1.6 eV, suggesting these nodal fluctuations might be protected from dissipation and crucial for high-temperature superconductivity.