Reviews on the most recent advances in hydrogen science, including cutting-edge fundamental studies in condensed matter physics with hydrogen-containing materials.

Multiple superconductivity wad found in the novel spin-triplet superconductor UTe₂, which is called “Silicon of Quantum Computers”. A complicated spin-triplet state is realized as a consequence of spin degree of freedom. This result will lead to a new state of topological superconductivity.

In quantum liquids, large differences are observed owing to differences in quantum statistics. The physical properties of liquid ³He (Fermion) and ⁴He (Boson) are considerably different at low temperatures. After the discovery of superconductivity in electron (i.e., Fermion) systems, a similar pairing ordered state was expected for ³He. Remarkably, the observed ordered state of ³He was more surprising than expected, multiple superfluid phases in the T–P phase diagram. The origin of the multiple phases was attributed to ferromagnetic interactions in the p-wave symmetry state.

We reveal magnetic degrees of freedom of Majorana fermions and find a new type of response that are distinct from those of conventional electrons.

The nonlinear conduction (the deviation from Ohm's law) has been discovered universally in various correlated materials. This may be explained by the percolation conduction in disordered materials.