Possible Z2 phase and spin-charge separation in electron-doped cuprate superconductors

Tiago C. Ribeiro; Xiao-Gang Wen

doi:10.1103/PhysRevB.68.024501

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Possible Z2 phase and spin-charge separation in electron-doped cuprate superconductors

Tiago C. Ribeiro, Xiao-Gang Wen

DOI 10.1103/PhysRevB.68.024501 · Physical Review B

T1

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Abstract

The SU(2) slave-boson mean-field theory for the tt′J model is analyzed. The role of next-nearest-neighbor hopping t′ on the phase diagram is studied. We find a pseudogap phase in hole-doped (HD) materials (where t′<0). The pseudogap phase is a U(1) spin liquid (the staggered-flux phase) with a U(1) gauge interaction and no fractionalization. This agrees with experiments on HD samples. The same calculation also indicates that a positive t′ favors a Z2 state with true spin-charge separation. The Z2 state that exists when t′≳0.5J can be a candidate for the pseudogap phase of electron-doped (ED) cuprates (if such a phase exists). The experimental situation in ED materials is also addressed.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
Pr2-xCexCuO4-y Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown
La2-xCexCuO4-y Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown