Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry

Abstract FeTe0.5Se0.5/Bi2Te3 heterostructure is a promising new platform in the journey toward topological quantum computation, considering that first, FeTe0.5Se0.5 (FTS) is itself known to be a topological superconductor (TSC) and second, the heterostructure has topological interface states that ca...

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Main Authors: Debarghya Mallick, Hee Taek Yi, Xiaoyu Yuan, Seongshik Oh
Format: Article
Language:English
Published: Wiley 2025-07-01
Series:Advanced Science
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Online Access:https://doi.org/10.1002/advs.202504430
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author Debarghya Mallick
Hee Taek Yi
Xiaoyu Yuan
Seongshik Oh
author_facet Debarghya Mallick
Hee Taek Yi
Xiaoyu Yuan
Seongshik Oh
author_sort Debarghya Mallick
collection DOAJ
description Abstract FeTe0.5Se0.5/Bi2Te3 heterostructure is a promising new platform in the journey toward topological quantum computation, considering that first, FeTe0.5Se0.5 (FTS) is itself known to be a topological superconductor (TSC) and second, the heterostructure has topological interface states that can be proximitized into TSC even if FTS fails to become TSC on its own. Here, it is shown that this system exhibits quasi‐2D superconductivity, and utilizing the standard in‐plane magneto‐transport measurements, two‐fold anisotropy (a.k.a nematicity) is discovered in longitudinal resistance (Rxx) and critical current (Ic) measurements, even though the system exhibits globally 12‐fold symmetry. Then, similar measurements are carried out on a polycrystalline niobium (Nb) thin film, a well‐known s‐wave elemental superconductor, and a similar two‐fold symmetry is found even for this Nb system. This implies either that nematic behavior is ubiquitous or that the in‐plane magneto‐transport measurement scheme routinely used to detect nematicity, is not a reliable method to probe nematicity. It is shown that the angle‐dependent response of vortices in the superconducting regime to the magnetic Lorentz force is very likely the main cause behind the ubiquitous nematic behaviors of this measurement scheme. In other words, this measurement scheme is intrinsically two‐fold, and is therefore not suitable to detect the nematicity. Accordingly, all the previous reports of nematicity based on similar measurement practices, reported on various samples, including thin films, bulk crystals, and exfoliated flakes, need to be reinterpreted.
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spelling doaj-art-1ada11b634a743eeb4e7c309f53d8bb72025-08-20T03:15:29ZengWileyAdvanced Science2198-38442025-07-011228n/an/a10.1002/advs.202504430Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement GeometryDebarghya Mallick0Hee Taek Yi1Xiaoyu Yuan2Seongshik Oh3Rutgers The State University of New Jersey 136 Frelinghuysen Road Piscataway NJ 08854 USARutgers The State University of New Jersey 136 Frelinghuysen Road Piscataway NJ 08854 USARutgers The State University of New Jersey 136 Frelinghuysen Road Piscataway NJ 08854 USARutgers The State University of New Jersey 136 Frelinghuysen Road Piscataway NJ 08854 USAAbstract FeTe0.5Se0.5/Bi2Te3 heterostructure is a promising new platform in the journey toward topological quantum computation, considering that first, FeTe0.5Se0.5 (FTS) is itself known to be a topological superconductor (TSC) and second, the heterostructure has topological interface states that can be proximitized into TSC even if FTS fails to become TSC on its own. Here, it is shown that this system exhibits quasi‐2D superconductivity, and utilizing the standard in‐plane magneto‐transport measurements, two‐fold anisotropy (a.k.a nematicity) is discovered in longitudinal resistance (Rxx) and critical current (Ic) measurements, even though the system exhibits globally 12‐fold symmetry. Then, similar measurements are carried out on a polycrystalline niobium (Nb) thin film, a well‐known s‐wave elemental superconductor, and a similar two‐fold symmetry is found even for this Nb system. This implies either that nematic behavior is ubiquitous or that the in‐plane magneto‐transport measurement scheme routinely used to detect nematicity, is not a reliable method to probe nematicity. It is shown that the angle‐dependent response of vortices in the superconducting regime to the magnetic Lorentz force is very likely the main cause behind the ubiquitous nematic behaviors of this measurement scheme. In other words, this measurement scheme is intrinsically two‐fold, and is therefore not suitable to detect the nematicity. Accordingly, all the previous reports of nematicity based on similar measurement practices, reported on various samples, including thin films, bulk crystals, and exfoliated flakes, need to be reinterpreted.https://doi.org/10.1002/advs.202504430iron‐based superconductormagneto‐electric transportnematicitythin filmtopological superconductor
spellingShingle Debarghya Mallick
Hee Taek Yi
Xiaoyu Yuan
Seongshik Oh
Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
Advanced Science
iron‐based superconductor
magneto‐electric transport
nematicity
thin film
topological superconductor
title Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
title_full Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
title_fullStr Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
title_full_unstemmed Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
title_short Ubiquity of Rotational Symmetry Breaking in Superconducting Films, From Fe(Te,Se)/Bi2Te3 to Nb, and the Effect of Measurement Geometry
title_sort ubiquity of rotational symmetry breaking in superconducting films from fe te se bi2te3 to nb and the effect of measurement geometry
topic iron‐based superconductor
magneto‐electric transport
nematicity
thin film
topological superconductor
url https://doi.org/10.1002/advs.202504430
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