Exploring hot topics in condensed matter physics and materials science

Lately, I have been contemplating hot topics in condensed matter physics and materials science that could be interesting for students seeking a suitable research group to carry out their PhD or B.Sc./M.Sc. research projects. I want to share my personal list with the readers of this blog. Disclaimer: Certainly, this list is incomplete and possibly highly subjective. Nevertheless, I do believe that it may serve as an inspiration for interested readers. 

• Quantum computing. Not sure whether this is just a current hype, but it deserves a top spot. Note the significant overlap with other fields beyond condensed matter physics, such as atomic, molecular and optical physics. 
• Superconductivity. This phenomenon actually got me into condensed matter physics in the first place. The research community has constantly renewed with discoveries of entirely new and unexpected classes of superconducting materials, such as cuprates, nickelates, and hydrides (under extremely high pressures). Superconductors have also gained public attention due to paper retraction scandals and erroneous claims of room-temperature superconductivity, see for example this article on the material LK-99. 
• Semiconductors. Yet another fascinating material class. Personally, I currently work on silicon carbide, a wide bandgap (power) semiconductor. There is a lot of excitement around SiC and GaN, which are materials that are in the process of replacing pure silicon, at least for certain high-voltage and high-frequency applications. Another interesting candidate for future power electronics applications is gallium oxide. A further exciting direction is semiconductor processing using extreme ultraviolet (EUV) lithography, which allows for patterning of chips with feature sizes down to 3 nm (and perhaps even less in the future). Overall, I want to emphasize that there is a high demand for skilled workers in the semiconductor industry. Consequently, it may be a smart career choice to get involved in this subfield.
• Magnetism and magnetic materials. This is one of the largest (and possibly oldest?) subfields of condensed matter physics, but has not lost its appeal. Magnetic hard drives are crucial for efficient data storage and still undergoing major evolution (here, I mention heat-assisted magnetic recording as a current example). Spin electronics, a novel approach, could find application in brain-inspired computing and other unconventional paradigms. Lastly, let me highlight ongoing research efforts on new permanent magnets for power applications, high entropy alloys, and magnetic nanoparticles for medical applications (e.g., tumor treatment). There is still a lot to do and to discover! 
  
• Computational materials discovery. In times of increased computational performance and artificial intelligence, this has become a growing and fascinating field where researchers try to find and design new materials with desirable properties. Could this approach be used to produce a room-temperature superconductor or highly efficient thermoelectric materials? It's conceivable, and we can expect impressive research output from this field.  
• Two-dimensional materials. More than 13 years after the Nobel Prize for the discovery of graphene, there have been significant new developments: twisted bilayers, magic-angle graphene, boron nitride, MXenes, etc. There is even a Graphene Flagship program initiated by the European Union. Numerous existing and future applications! 
• Majorana fermions. Lots of controversies whether these quasiparticles have already been seen experimentally in condensed matter systems. I think that there is still much research to be done. 
• Ferroelectrics and multiferroics. These material classes have been around for a while, but I am certain that there is more to come. 
• Topological materials. The Nobel Prize in 2016 was awarded for topological concepts in (theoretical) condensed matter physics. There have been a lot of research groups working on topological materials over the past few years.  
  
• Strongly correlated systems. Some of the smartest condensed matter physicist I have met are working in this subfield. Complex and fascinating physics! 
  
• Non-equilibrium condensed matter physics. Lots of opportunities and challenges in this subfield as well!
  

What would you add to this list? Please let me (and other readers) know in the comments!