Momentum-Resolved Charge Dynamics in quasi-low Dimensional Mott Systems : Perspective from a Novel Spectroscopy

 
M.Z. Hasana, Y.Lia and Y-D. Chuanga,b 
 
aDepartment of Physics, Princeton University, Princeton, NJ 08544, USA; bAdvanced Light Source, LBNL, Berekely, Ca 94720, USA ( mzhasan@princeton.edu )
 
 
Electron dynamics in Mott systems continues to be an unsolved problem in physics despite more than half-century of intense research efforts. Well-developed momentum-resolved spectroscopies such as angle-resolved photoemission and neutron scattering or optical measurements cannot probe the full Mott gap in a momentum-resolved manner or study the momentum-dependence of the unoccupied states (upper Hubbard band). We have recently reported observation of several novel aspects of cuprate electronic structure such as highly dispersive particle-hole pair excitations, anisotropy of Mott gap excitations [1], lowest energy momentum state of the upper Hubbard band in 2-D, its doping evolution and dispersion relation of holons (spinless charge excitations) in 1-D [2] using a novel scattering technique – high resolution resonant inelastic x-ray scattering. Future directions for this charge coupling probe include possible study of dynamic stripes, (pi, pi)-resonance, anisotropy of 2-delta (full) pseudogap and electron-phonon coupling. 

Reference

1 Hasan, M.Z., Isaacs E., et.al. (2000) Science, 288, 1811.

2 Hasan, M.Z., Montano P. A., et.al. (2002), Phys. Rev. Lett., 88, 177403.