Interacting composite fermions

• Published in: Solid state communications Vol. 117; no. 3; pp. 117 - 122
• Main Authors: Jain, J.K, Kamilla, R.K, Park, K, Scarola, V.W
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2001; Elsevier
• Subjects: C. Symmetry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Fractional quantum Hall effect; D. Quantum Hall effect; Electron states; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in interface structures; Exact sciences and technology; Fermions in reduced dimensions (anyons, composite fermions, Luttinger liquid, etc.); Physics; Quantum hall effect (including fractional); Theories and models of many electron systems; D. Quantum Hall effect; 71.10.Pm; D. Fractional quantum Hall effect; 71.10.L; 73.40.H; C. Symmetry; Fractional quantum Hall effect; Fermion systems; Excitons; Cooper pairs; Wigner crystals; Dispersion relations; Theoretical study; Instability; Landau levels
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/S0038-1098(00)00440-3

Even though much of the dramatic physics of two-dimensional electrons in a high magnetic field is explicable in terms of weakly interacting composite fermions (CFs), the inter-CF interaction is responsible for many interesting, non-trivial phenomena. Here, we discuss four examples. (i) At small filling factors, a softening of the roton mode destroys the fractional Hall effect, giving way to the Wigner crystal. (ii) In higher Landau levels, the fractional Hall effect is destroyed due to a collapse of the energy of the neutral exciton. (iii) At ν=5/2, the Fermi sea of CFs is unstable to Cooper pairing of CFs, thereby opening up a gap and producing a fractional Hall effect. (iv) Prior to the transition into the Wigner crystal, the CF liquid exhibits the Bloch instability into a magnetically ordered, spontaneously broken symmetry phase.