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SC Zhang

Publications and source records attributed to SC Zhang.

At least 19 recordsLinked to original sources

Interrelation of superconducting and antiferromagnetic gaps in high- T(c) compounds: A test case for the SO(5) theory

Recent angle resolved photoemission data, which found evidence for a d-wave-like modulation of the antiferromagnetic gap, suggest an intimate interrelation between the antiferromagnetic insulator and the superconductor with its d-wave gap. It is shown here that a projected SO(5) theory, which explicitly takes the Mott-Hubbard gap into account, correctly describes the observed gap characteristics. Specifically, it accounts for the order of magnitude difference between the antiferromagnetic gap modulation and the superconducting gap and is also consistent with the gap dispersion.

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A Unified Theory Based on SO(5) Symmetry of Superconductivity and Antiferromagnetism

The complex phase diagram of high-critical temperature (Tc) superconductors can be deduced from an SO(5) symmetry principle that unifies antiferromagnetism and d-wave superconductivity. The approximate SO(5) symmetry has been derived from the microscopic Hamiltonian, and it becomes exact under renormalization group flow toward a bicritical point. This symmetry enables the construction of a SO(5) quantum nonlinear final sigma model that describes the phase diagram and the effective low-energy dynamics of the system. This model naturally explains the basic phenomenology of the high-Tc superconductors from the insulating to the underdoped and the optimally doped region.

Journal Article↗