Effective mass suppression in a ferromagnetic two-dimensional electron liquid

We present numerical calculations of the electron effective mass in an interacting ferromagnetic two-dimensional electron system. We consider quantum interaction effects associated with the charge-density fluctuation-induced many-body vertex corrections. Our theory, which is free of adjustable parameters, reveals that the effective mass is suppressed (relative to its band value) in the strong-coupling limit, in good agreement with recent experimental results.

Figure 1

(Color online) Many-body effective mass as a function of $r_s$ for $0\le r_s\le 22$ for a ferromagnetic 2DES.

Figure 2

(Color online) Many-body effective mass as a function of $r_s$ for $0\le r_s\le 22$ for the ferromagnetic 2DES in comparison to experiments in Refs. 8, 16. Different symbols denote different samples; triangles: A, squares: B, circles: C, and diamonds: D.

Figure 3

(Color online) Many-body on-shell effective mass as a function of $k/k_{\text{F}}$ at $r_s=5$ for 2DES with the combined effect of charge fluctuations in comparison to paramagnetic 2DES.

Figure 4

(Color online) Renormalization constant $Z_{\uparrow }$ as a function of $r_s$ for $0<r_s<22$ for a ferromagnetic 2DES.