2010/12/05 by Sanjoy K. Sarker, Sarker, Sanjoy K., Timothy Lovorn +1
Engineering · Physics and Astronomy · #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum Chromodynamics and Particle Interactions #Superconducting Materials and Applications #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.1012.1058
openalex publication_date 2010/12/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recently, we have solved the long-standing problem of connecting the physics\nof the Mott insulator to the underdoped regime of the t-J model [PRB 82,\n014504, 2010]. We have derived a renormalized Hamiltonian valid for small\ndoping (x) which is characterized by a spin gap, and sublattice preserving\nhopping by a hole, and by a pair of holes, both accompanied by a spin-singlet\nbackflow. The phase diagram obtained by continuing the spin states from half\nfilling reproduces the phases of the cuprates. Remarkably, confinement of\nmetallic conduction to 2d emerges from the theory (i.e., it is not assumed).\nHere we show that the Hamiltonian naturally leads to a pairing mechanism in\nwhich the pair has a dual character. Its spin part is a spinon singlet which\n(2d) condenses below T*. The charge part is a real-space holon pair formed at\nTp < T*, which undergoes a (3d) Bose-Einstein condensation at Tc < Tp. While\nneither is observable separately, the combination is, as a well-defined\nexcitation of momentum q, and energy w(q). The mechanism is consistent with the\nsmall superfluid density, the decline of Tc at small doping, and the existence\nof pairs above Tc in cuprates, as indicated by the observation of diamagnetism\nand Nernst effect.\n