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تسجيل مستخدم جديدSignatures of magnetic Weyl fermion annihilation
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Correlated topological magnets are emerging as a new class of quantum materials, exhibiting exotic interacting fermions and unconventional phase transitions. Despite considerable interest, direct observation of the magnetic manipulation of topological quasiparticles remains limited. Here we report a correlated topological phase transition in a kagome spin-orbit semimetal, examined by high-resolution photoemission spectroscopy. By modulating the magnetic order, we observe a clear exchange gap collapse in our spectra, associated with a large renormalization of a spin-orbit-gapped Weyl loop at the Fermi level. This unexpected response suggests the collapse of opposite-spin partner ferromagnetic Weyl loops into a paramagnetic Dirac loop. Taken together with $ab$ $initio$ calculation, our results further indicate that oppositely-charged Weyl points pair up and annihilate under collapse, and the Fermi arc surface states are removed. Our findings suggest a novel topological phase transition driven by magnetic interactions, guiding future exploration of renormalized topology under correlated order parameters.
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