TY - JOUR
T1 - Large spin-orbit effects in small interacting quantum dots
AU - Murthy, Ganpathy
AU - Shankar, R.
PY - 2007/2/22
Y1 - 2007/2/22
N2 - We consider small ballistic quantum dots weakly coupled to leads in the chaotic regime and look for significant spin-orbit effects. We find that these effects can become quite prominent in the vicinity of degeneracies of many-body energies. We illustrate the idea by considering a case where the intrinsic exchange term -J S2 brings singlet and triplet many-body states near each other, while an externally tunable Zeeman term then closes the gap between the singlet and one of the triplet states (with spin projection parallel to the external field). Near this degeneracy, the spin-orbit coupling leads to a striking temperature dependence of the conductance, with observable effects of order unity at temperatures lower than the strength of the spin-orbit coupling. Under favorable circumstances, spelled out in the paper, these order-unity effects in the conductance persist to temperatures much higher than the spin-orbit coupling strength. Our conclusions are unaffected by the presence of nonuniversal perturbations. We suggest a class of experiments to explore this regime.
AB - We consider small ballistic quantum dots weakly coupled to leads in the chaotic regime and look for significant spin-orbit effects. We find that these effects can become quite prominent in the vicinity of degeneracies of many-body energies. We illustrate the idea by considering a case where the intrinsic exchange term -J S2 brings singlet and triplet many-body states near each other, while an externally tunable Zeeman term then closes the gap between the singlet and one of the triplet states (with spin projection parallel to the external field). Near this degeneracy, the spin-orbit coupling leads to a striking temperature dependence of the conductance, with observable effects of order unity at temperatures lower than the strength of the spin-orbit coupling. Under favorable circumstances, spelled out in the paper, these order-unity effects in the conductance persist to temperatures much higher than the spin-orbit coupling strength. Our conclusions are unaffected by the presence of nonuniversal perturbations. We suggest a class of experiments to explore this regime.
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U2 - 10.1103/PhysRevB.75.075327
DO - 10.1103/PhysRevB.75.075327
M3 - Article
AN - SCOPUS:33847203243
SN - 1098-0121
VL - 75
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 7
M1 - 075327
ER -