In this new picture, the superconducting state in cuprates is characterized by the presence of competing orders, such as charge order and spin order. These competing orders lead to the formation of electronic puddles or clusters, where superconductivity can coexist with other types of order. The boundaries between these puddles are resistive, which gives rise to a finite dc resistance in the superconducting state.
The strength of these competing orders and the size of the superconducting puddles are controlled by several factors, including doping, temperature, and magnetic field. By tuning these parameters, it is possible to control the amount of disorder and the degree of electronic correlations, which in turn affect the superconducting properties of the material.
This new understanding of superconductivity in cuprates provides a framework for understanding the anomalous properties of these materials and suggests new ways to design materials with even higher superconducting transition temperatures and improved performance.
Here is a more detailed explanation of the key concepts:
Electronic puddles:
In cuprates, the superconducting state is not uniform. Instead, it consists of small regions, called puddles, where superconductivity coexists with other types of order, such as charge order or spin order. The size and shape of these puddles depend on the material and the conditions under which it is superconductivity.
Competing orders:
The formation of electronic puddles is a result of the competing interactions between electrons in cuprates. These interactions include Coulomb repulsion, electron-phonon coupling, and magnetic exchange interactions. The relative strength of these interactions determines the type of order that dominates the material. In some cases, superconductivity can coexist with other orders, while in other cases, it is completely suppressed.
Disorder:
Disorder plays a crucial role in the properties of cuprates. It can be caused by impurities, defects, or even thermal fluctuations. Disorder can disrupt the formation of electronic puddles and lead to a decrease in the superconducting transition temperature. However, in some cases, disorder can also induce superconductivity in materials that would otherwise be non-superconducting.
By understanding the interplay between electronic correlations, quantum fluctuations, and disorder, we can gain a deeper understanding of the unconventional superconductivity in cuprates and design materials with improved properties.
