Hierarchy of modes in an interacting system

Add to your list(s) Download to your calendar using vCal

• Oleksandr Tsyplyatyev, University of Birmingham
• Wednesday 29 October 2014, 14:15-15:15
• Mott Seminar Room, Cavendish Laboratory, Department of Physics.

If you have a question about this talk, please contact Teri Bartlett.

Studying interacting fermions in 1D at high energy, we find a hierarchy in the spectral weights of the excitations theoretically and we observe evidence for second-level excitations experimentally. Diagonalising a model of fermions (without spin), we show that levels of the hierarchy are separated by powers of R^2/L2, where R is a length-scale related to interactions and L is the system length. The first-level (strongest) excitations form a mode with parabolic dispersion, like that of a renormalised single particle. The second-level excitations produce a singular power-law line shape to the first-level mode and multiple power-laws at the spectral edge. We measure momentum-resolved tunnelling of electrons (fermions with spin) from/to a wire formed within a GaAs heterostructure, which shows parabolic dispersion of the first-level mode and well-resolved spin-charge separation at low energy with appreciable interaction strength. We find structure resembling the second-level excitations, which dies away quite rapidly at high momentum.

This talk is part of the Semiconductor Physics Group Seminars series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room, Cavendish Laboratory, Department of Physics
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• School of Physical Sciences
• Semiconductor Physics Group Seminars
• Thin Film Magnetic Talks

Note that ex-directory lists are not shown.