Scientists are continually exploring the boundaries of superconductivity, a state of matter characterized by the complete absence of electrical resistance, which holds great promise for revolutionizing technology and advancing quantum computing. A recent breakthrough by researchers at the RIKEN Center for Emergent Matter Science (CEMS) underscores an incredible new avenue of control over this phenomenon, revealing that by merely twisting atomically thin layers of materials within a layered device, one can tune crucial superconducting properties. This innovative approach not only opens new doors for future materials but also enhances our understanding of the intricate relationships that govern superconducting systems.
Superconductivity is critical for a variety of advanced technologies, where efficient energy transfer is essential. Cooper pairs, which consist of pairs of electrons bound together at low temperatures, play a fundamental role in the emergence of superconductivity. The energy required to break apart these Cooper pairs is known as the superconducting gap, and the behavior of this gap is pivotal in determining the operational efficacy of superconductors. Traditionally, the larger the superconducting gap, the more likely it is for superconductivity to persist at higher temperatures, making it indispensable for accessible technological applications. This study emphasizes the importance of controlling the superconducting gap, particularly in light of demands for improving the functionality of quantum devices.
Historically, attempts to manipulate the superconducting gap have been concentrated on controlling the physical properties at the real-space level, focusing on where particles are situated within the material. However, efforts to achieve similar levels of control within momentum space—a framework that represents the energy states of a system—have proven elusive until now. The ability to fine-tune the superconducting gap in momentum space is seen as a necessary step to escalate the development of superconductors and their applications in quantum computing, essentially a prerequisite for the next generation of high-performance superconducting materials.
To unveil this potential, the research team focused on ultrathin layers of niobium diselenide (NbSe2), a well-regarded superconductor, laid upon a graphene substrate. By employing state-of-the-art imaging and fabrication techniques, notably spectroscopic-imaging scanning tunneling microscopy coupled with molecular beam epitaxy, the researchers were able to precisely vary the twist angles of these layers. This delicate adjustment resulted in measurable alterations in the superconducting gap as observed within momentum space. This key observation introduces a previously unexplored method for tuning superconducting properties, paving the way for vast enhancements in material design and function.
Masahiro Naritsuka, the study’s lead author, noted that twisting the ultra-thin layers provides an exquisite control mechanism over superconductivity by selectively adjusting the superconducting gap across targeted regions within momentum space. Among the striking discoveries from this research were the emergence of unique flower-like modulation patterns within the superconducting gap, patterns that do not align with the crystallographic axes of either niobium diselenide or graphene. This unexpected finding highlights the pivotal role that twisting plays in influencing superconducting properties, a nuance that may have significant implications for designing future superconducting materials.
The research team’s findings not only deepen the fundamental understanding of how superconducting systems interact across layers but also mark a critical step toward the engineering of superconductors that exhibit tailored properties. By controlling the superconducting gap through twists, the researchers have laid the groundwork for future innovations that could lead to more energy-efficient technologies and groundbreaking advances in quantum computing. Tetsuo Hanaguri, a senior author of the paper, emphasizes that this research opens the door to further inquiries, particularly concerning the integration of magnetic layers into these structures. Such additions could enable selectivity in both spin and momentum, thereby unveiling entirely new research avenues in the field of superconductivity.
As scientists delve deeper into understanding the complex interplay of factors affecting superconductivity, the implications of this research are vast. The ability to manipulate superconducting properties through twisting may revolutionize not only the materials engineering landscape but also the design and function of devices that rely on superconductivity. By enhancing energy efficiency and lowering operational thresholds, the potential applications of these findings could extend into various domains, including power transmission, electromagnetic enhancements, and next-generation quantum computing hardware.
Moreover, continued exploration into the integration of magnetic elements into this framework may lead to materials that exhibit both superconductive and magnetic properties concurrently, vastly expanding the capabilities of conventional superconductors. This multidisciplinary approach to material science could yield breakthroughs that transcend current limitations, culminating in the practical application of superconductors in areas previously thought impossible.
As contemporary challenges in energy consumption and computation intensify, the relevance of such research becomes ever more critical. Innovations in superconducting materials are not merely theoretical exercises; they represent tangible solutions to the world’s growing energy demands. The journey toward high-temperature superconductors that operate at ambient conditions may still be in its infancy, but findings like those from the RIKEN CEMS team serve as vital stepping stones on this path.
In conclusion, the research conducted at the RIKEN Center for Emergent Matter Science exemplifies a significant leap forward in our capability to control superconductivity through strategic manipulation of material properties. As scientists harness these emergent techniques, the implications on a global scale could translate into benefits that extend beyond mere energy efficiency. With continued research, we are poised to unravel even more about superconductivity and its transformative potential for technology and society at large.
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Subject of Research:
Article Title: Superconductivity controlled by twist angle in monolayer NbSe2 on graphene
News Publication Date: 20-Mar-2025
Web References:
References: DOI: 10.1038/s41567-025-02828-6
Image Credits:
Keywords
Superconductivity, Quantum Computing, Materials Engineering, Niobium Diselenide, Graphene, Energy Efficiency
