Studying defects and imperfections in unconventional superconductors is paramount for fundamental and applied research. Defects play a multifaceted role, from decreasing quality and performance in some situations to enhancing desired properties in others, and as a useful probe and a tool to study the fundamental aspects of superconductivity. The examples are quantum decoherence in superconducting qubits, pinning and critical current in superconducting magnets, and in determining the symmetry of the order parameter, respectively. Studying defects and imperfections can provide insights into the underlying physics of unconventional superconductivity, shedding light on the mechanisms that govern the emergence of superconductivity in these materials, as well as the factors that limit their critical current densities and their stability at elevated temperatures and magnetic fields. Understanding the complex mechanisms through which defects influence the properties of superconductors is key to advancing the development and optimization of high performance superconducting materials for modern technologies.
The importance of defects was recognized in the early days of superconductivity research when seminal works appeared, notably the Abrikosov-Gor’kov theory of pair-breaking by magnetic impurities and the so-called Anderson theorem of the protection of an isotropic superconducting state from non-magnetic scattering. In the later years, increasingly more complex situations were considered, such as response to scattering in multiband and anisotropic superconductors. The importance of defects for determining basic properties, for example, the superconducting gap structure, has become even more prominent with the discoveries of unconventional superconductors, from heavy fermions to high-Tc cuprates to, most recently, iron-based superconductors. For example, in high-Tc cuprates, the modification of the low-temperature variation of the London penetration depth was one of the earliest solid arguments for the d-wave pairing in these compounds. It is also suggested that intrinsic disorder at the unit cell level is responsible for some unusual properties of the cuprates [Peter’s work on the atomic disorder in BSCCO]. In the present day, attention to topologically non-trivial states that may protect from disorder scattering only adds to the importance of this field of study.
Defects and imperfections in superconductors can significantly alter their electronic structure and lead to interesting behavior, such as the emergence of new electronic states and modifications of the transport, magnetic and optical properties. Understanding the influence of these defects on the superconducting properties of unconventional superconductors is therefore crucial for developing new materials with high transition temperatures and improved properties for technological applications. This includes the fabrication of tailored superconductors for practical devices, such as superconducting qubits, sensitive detectors, wires, magnets, and energy storage systems.
In this Research Topic, “Disorder and Superconductivity: a 21st-century update”, Frontiers in Physics Open-Access online collection of articles will highlight current understanding and trends on the title topic focusing on modern research, both fundamental and applied, experimental and theoretical, conventional and unconventional superconductors, native and artificial disorder. It is not intended to be comprehensive but rather broad coverage. Should you accept this invitation, the article submission will open in November 2023 and close in December 2023. Articles will appear online when they are accepted and processed for online publication.
Please note this Research Topic is open to invited contributions only.
Studying defects and imperfections in unconventional superconductors is paramount for fundamental and applied research. Defects play a multifaceted role, from decreasing quality and performance in some situations to enhancing desired properties in others, and as a useful probe and a tool to study the fundamental aspects of superconductivity. The examples are quantum decoherence in superconducting qubits, pinning and critical current in superconducting magnets, and in determining the symmetry of the order parameter, respectively. Studying defects and imperfections can provide insights into the underlying physics of unconventional superconductivity, shedding light on the mechanisms that govern the emergence of superconductivity in these materials, as well as the factors that limit their critical current densities and their stability at elevated temperatures and magnetic fields. Understanding the complex mechanisms through which defects influence the properties of superconductors is key to advancing the development and optimization of high performance superconducting materials for modern technologies.
The importance of defects was recognized in the early days of superconductivity research when seminal works appeared, notably the Abrikosov-Gor’kov theory of pair-breaking by magnetic impurities and the so-called Anderson theorem of the protection of an isotropic superconducting state from non-magnetic scattering. In the later years, increasingly more complex situations were considered, such as response to scattering in multiband and anisotropic superconductors. The importance of defects for determining basic properties, for example, the superconducting gap structure, has become even more prominent with the discoveries of unconventional superconductors, from heavy fermions to high-Tc cuprates to, most recently, iron-based superconductors. For example, in high-Tc cuprates, the modification of the low-temperature variation of the London penetration depth was one of the earliest solid arguments for the d-wave pairing in these compounds. It is also suggested that intrinsic disorder at the unit cell level is responsible for some unusual properties of the cuprates [Peter’s work on the atomic disorder in BSCCO]. In the present day, attention to topologically non-trivial states that may protect from disorder scattering only adds to the importance of this field of study.
Defects and imperfections in superconductors can significantly alter their electronic structure and lead to interesting behavior, such as the emergence of new electronic states and modifications of the transport, magnetic and optical properties. Understanding the influence of these defects on the superconducting properties of unconventional superconductors is therefore crucial for developing new materials with high transition temperatures and improved properties for technological applications. This includes the fabrication of tailored superconductors for practical devices, such as superconducting qubits, sensitive detectors, wires, magnets, and energy storage systems.
In this Research Topic, “Disorder and Superconductivity: a 21st-century update”, Frontiers in Physics Open-Access online collection of articles will highlight current understanding and trends on the title topic focusing on modern research, both fundamental and applied, experimental and theoretical, conventional and unconventional superconductors, native and artificial disorder. It is not intended to be comprehensive but rather broad coverage. Should you accept this invitation, the article submission will open in November 2023 and close in December 2023. Articles will appear online when they are accepted and processed for online publication.
Please note this Research Topic is open to invited contributions only.
