Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2011 Jun 10;106(23):236801. doi: 10.1103/PhysRevLett.106.236801. Epub 2011 Jun 6.
The Pfaffian phase in the proximity of a half-filled Landau level is understood to be a p+ip superconductor of composite fermions. We consider the properties of this paired quantum Hall phase when the pairing energy is small, i.e., in the weak-coupling, BCS limit, where the coherence length is much larger than the charge screening length. We find that, as in a type I superconductor, vortices attract so that, upon varying the magnetic field from its magic value at ν=5/2, the system exhibits Coulomb frustrated phase separation. We propose that the weakly and strongly coupled Pfaffians exemplify a general dichotomy between type I and type II quantum Hall fluids.
在接近半满朗道能级的 Pfaffian 相中，被认为是复合费米子的 p+ip 超导体。当配对能很小时，即处于弱耦合、BCS 极限时，相干长度远大于电荷屏蔽长度，我们考虑了这种配对量子霍尔相的性质。我们发现，就像在 I 型超导体中一样，涡旋相互吸引，因此，在磁场从ν=5/2 的魔术值变化时，系统表现出库仑受挫的相分离。我们提出，弱耦合和强耦合 Pfaffian 分别代表了 I 型和 II 型量子 Hall 流体之间的一般二分法。
