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We report the achieving of depairing current limit along c-axis in Fe1+yTe1−xSex single crystals. A series of crystals with Tc ranging from 8.6 K to 13.7 K (different amount of excess Fe, y) were fabricated into c-axis bridges with a square-micrometer cross-section. The critical current density, Jc, was directly estimated from the transport current-voltage measurements. The transport Jc reaches a very large value, which is about one order of magnitude larger than the depinning Jc, but comparable to the calculated depairing Jc ∼ 2 × 10 6 A/cm 2 at 0 K, based on the Ginzburg-Landau (GL) theory. The temperature dependence of the depairing Jc follows the GL-theory (∝ (1-T /Tc) 3/2 ) down to ∼ 0.83 Tc, then increases with a reduced slope at low temperatures, which can be qualitatively described by the Kupriyanov-Lukichev theory. Our study provides a new route to understand the behavior of depairing Jc in iron-based superconductors in a wide temperature range. * sunyue@phys.aoyama.ac.jp † hkitano@phys.aoyama.ac.jp

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