Emergent electronic phenomena in iron-based superconductors have been at the forefront
of condensed matter physics for more than a decade. Much has been learned about the …

High-temperature superconductivity and a wide variety of exotic superconducting states
discovered in FeSe-based materials have been at the frontier of research on condensed …

Abstract The BCS-BEC (Bardeen-Cooper-Schrieffer–Bose-Einstein-condensate) crossover
from strongly overlapping Cooper pairs to non-overlapping composite bosons in the strong …

The interplay among magnetism, electronic nematicity, and superconductivity is the key
issue in strongly correlated materials including iron-based, cuprate, and heavy-fermion …

We present resistivity and thermal-conductivity measurements of superconducting FeSe in
intense magnetic fields up to 35 T applied parallel to the ab plane. At low temperatures, the …

The crossover from the superconductivity of the Bardeen-Cooper-Schrieffer (BCS) regime to
the Bose-Einstein condensation (BEC) regime holds a key to understanding the nature of …

When a symmetry-breaking phase of matter is suppressed to a quantum critical point (QCP)
at absolute zero, quantum-mechanical fluctuations proliferate. Such fluctuations can lead to …

Unconventional superconductivity often competes or coexists with other electronic orders. In
iron-based superconductors, a central issue has been the relationship between …

Non-Fermi liquids are strange metals whose physical properties deviate qualitatively from
those of conventional metals due to strong quantum fluctuations. In this paper, we report …

The quantum vortex liquid (QVL) is an intriguing state of type-II superconductors in which
intense quantum fluctuations of the superconducting (SC) order parameter destroy the …