Solvable regime of disorder and interactions in ballistic nanostructures: Consequences for Coulomb blockade

作者: Ganpathy Murthy , R. Shankar , Damir Herman , Harsh Mathur

DOI: 10.1103/PHYSREVB.69.075321

关键词:

摘要: We provide a framework for analyzing the problem of interacting electrons in ballistic quantum dot with chaotic boundary conditions within an energy E T (the Thouless energy) Fermi energy. Within this window we show that interactions can be characterized by Landau Fermi-liquid parameters. When g, number (also dimensionless conductance when it has strong coupling to leads) dot, is large, find disordered solved saddle-point approximation which becomes exact as g → ∞ (as large-N theory). The infinite theory two phases function parameter u m channel angular momentum m: A weak-coupling phase where constant charging and exchange dominate low-energy physics, previous "universal Hamiltonian" treatments, strong-coupling same order Pomeranchuk transition clean systems (a spontaneous interaction-induced Fermi-surface distortion), but smeared pinned disorder. Thus, both disorder are crucial existence these phases. At finite critical point evolve into three regimes -1/g plane-weak- separated crossover lines from quantum-critical regime controlled point. In this, first part series, focus on consequences picture Coulomb Blockade experiments. employ analytical numerical methods predict statistics single-particle levels, peak spacings, heights, quasiparticle widths. regions, acquires width level spacing few Δ's due collective excitations. if odd, will (if isolated) orthogonal unitary ensemble exponentially small external flux or strongly coupled break time-reversal symmetry spontaneously. For any m, peak-spacing distribution broader than expected works even support at negative values, turn correlated heights. Ballistic/chaotic dots afford us unrivalled theoretical experimental control over simultaneous 1/g expansion our ability vary interaction much more readily bulk.

参考文章(138)
Sudip Chakravarty, Bertrand I. Halperin, David R. Nelson, Two-dimensional quantum Heisenberg antiferromagnet at low temperatures. Physical Review B. ,vol. 39, pp. 2344- 2371 ,(1989) , 10.1103/PHYSREVB.39.2344
K. Held, E. Eisenberg, B. L. Altshuler, Effect of spectral fluctuations on conductance-peak height statistics in quantum dots Physical Review B. ,vol. 66, pp. 033308- ,(2002) , 10.1103/PHYSREVB.66.033308
S. Lüscher, T. Heinzel, K. Ensslin, W. Wegscheider, M. Bichler, Signatures of spin pairing in chaotic quantum dots. Physical Review Letters. ,vol. 86, pp. 2118- 2121 ,(2001) , 10.1103/PHYSREVLETT.86.2118
U. Eckern, P. Schwab, Persistent Currents Versus Phase Breaking in Mesoscopic Metallic Samples Journal of Low Temperature Physics. ,vol. 126, pp. 1291- 1304 ,(2002) , 10.1023/A:1013891902631
Thomas Guhr, Axel Müller–Groeling, Hans A. Weidenmüller, Random-matrix theories in quantum physics: common concepts Physics Reports. ,vol. 299, pp. 189- 425 ,(1998) , 10.1016/S0370-1573(97)00088-4
Albert Schmid, Persistent currents in mesoscopic rings by suppression of charge fluctuations. Physical Review Letters. ,vol. 66, pp. 80- 83 ,(1991) , 10.1103/PHYSREVLETT.66.80
S. R. Patel, S. M. Cronenwett, D. R. Stewart, A. G. Huibers, C. M. Marcus, C. I. Duruöz, J. S. Harris, K. Campman, A. C. Gossard, Statistics of Coulomb Blockade Peak Spacings Physical Review Letters. ,vol. 80, pp. 4522- 4525 ,(1998) , 10.1103/PHYSREVLETT.80.4522
Y. Alhassid, T. Rupp, Effects of Spin and Exchange Interaction on the Coulomb-Blockade Peak Statistics in Quantum Dots Physical Review Letters. ,vol. 91, pp. 056801- 056801 ,(2003) , 10.1103/PHYSREVLETT.91.056801
Gonzalo Usaj, Harold U. Baranger, Coulomb-blockade peak-spacing distribution: Interplay of temperature and spin Physical Review B. ,vol. 64, pp. 201319- ,(2001) , 10.1103/PHYSREVB.64.201319