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DOE OSTI · 3008061

Quantifying Twist Angles in Cuprate Heterostructures with Anisotropic Raman Signatures

Lo Sardo, Flavia [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0009000141966384)·Esposito, Marina [University of Naples Federico II (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Napoli (Italy)]·Confalone, Tommaso [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0009000874536007)·Tremblay, Christophe [University of Sherbrooke, QC (Canada)]·Vinokur, Valerii M. [Terra Quantum AG, St. Gallen (Switzerland)]·Gu, Genda [Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000298863255)·Montemurro, Domenico [University of Naples Federico II (Italy)]·Massarotti, Davide [University of Naples Federico II (Italy)]·Tafuri, Francesco [University of Naples Federico II (Italy)] (ORCID:0000000307841454)·Nielsch, Kornelius [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0000000322717726)·Poccia, Nicola [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); University of Naples Federico II (Italy)] (ORCID:0000000179820113)·Haider, Golam [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany)] (ORCID:0000000153003764)
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Abstract

Artificially engineered twisted van der Waals (vdW) heterostructures have unlocked new pathways for exploring emergent quantum phenomena and strongly correlated electronic states. Many of these phenomena are highly sensitive to the twist angle, which can be deliberately tuned to tailor the interlayer interactions. This makes the twist angle a critical tunable parameter, emphasizing the need for precise control and accurate characterization during device fabrication. In particular, twisted cuprate heterostructures based on Bi 2 Sr 2 CaCu 2 O 8 + x (BSCCO) have demonstrated angle-dependent superconducting properties, positioning the twist angle as a key tunable parameter. However, the twisted interface is highly unstable under ambient conditions and vulnerable to damage from conventional characterization tools such as electron microscopy or scanning probe techniques. In this work, a fully non-invasive, polarization-resolved Raman spectroscopy approach is introduced for determining twist angles in artificially stacked BSCCO heterostructures. By analyzing twist-dependent anisotropic vibrational Raman modes, particularly utilizing the out-of-plane A 1g vibrational mode of Bi/Sr at ≈116 cm −1 , clear optical fingerprints of the rotational misalignment between cuprate layers are identified. The high-resolution confocal Raman setup, equipped with polarization control and RayShield filtering down to 10 cm −1 , allows for reliable and reproducible measurements without compromising the material's structural integrity.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYBi2Sr2CaCu2O8+Xanisotropic phonon modespolarization-resolved Raman spectroscopytwist angle metrologytwisted cuprate heterostructures

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Lo Sardo, Flavia [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0009000141966384), Esposito, Marina [University of Naples Federico II (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Napoli (Italy)], Confalone, Tommaso [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0009000874536007), Tremblay, Christophe [University of Sherbrooke, QC (Canada)], Vinokur, Valerii M. [Terra Quantum AG, St. Gallen (Switzerland)], Gu, Genda [Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000298863255), Montemurro, Domenico [University of Naples Federico II (Italy)], Massarotti, Davide [University of Naples Federico II (Italy)], Tafuri, Francesco [University of Naples Federico II (Italy)] (ORCID:0000000307841454), Nielsch, Kornelius [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); Technische Universität Dresden (Germany)] (ORCID:0000000322717726), Poccia, Nicola [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany); University of Naples Federico II (Italy)] (ORCID:0000000179820113), Haider, Golam [Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany)] (ORCID:0000000153003764). 2025-11-14. Quantifying Twist Angles in Cuprate Heterostructures with Anisotropic Raman Signatures. https://doi.org/10.1002/apxr.202500108

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