Matryoshka Transition
That Nature imposes an intricate order is obvious. How it does so is the quest of science. Much mystery remains.
Existence incessantly emerges from the quantum realm to the everyday, where classical physics applies, through 2 mechanisms: decoherence and perception.
The type of measurement determines whether a phenomenon will appear as quantum or classical. Quantum effects may be inferred using equipment. To the naked eye, such small-scale specificity is beyond observation. (Humans cannot consciously perceive quantum phenomena. Whether other life can is perhaps unknowable.) Hence, the world always appears classical.
Existence at the quantum scale is always coherently entangled: waves of possibilities (superpositions) which emerge at every instant via decoherence: environmental interactions that are thermodynamically irreversible. The emergence of observable phenomena requires localization and quantization, which appears as an absence of entanglement. Decoherence generates diversity.
Superconductivity Seam
The emergence of complexity is often tied to novel forms of collective behavior driven by strong interactions. Unconventional superconductors are archetypical examples for materials in which the competition and entwining of collective forms of behavior give rise not only to a complex phase diagram, but also to unexpected properties that have resisted all attempts of a theoretical explanation. ~ German American physicist Dirk Morr
Whereas superconductivity is of coherently-paired electrons with opposite spins and momenta, charge order involves orderliness in the arrangement of electrons and holes (electron absences) that have the same spin and momenta. Antiferromagnetism relies upon charge ordering.
Charge order and superconductivity are 2 competing pairing tendencies which cannot be simultaneously satisfied. This mutual exclusivity is on display when an antiferromagnetic material gives way to superconductivity.
In between these highly-ordered states is a transition phase which defies characterization, as it does not correspond with the Landau–Fermi liquid theory, which is the accepted model of how metallic fermions interact at low temperatures. Quantum states cannot be accounted for in this transitional gap.
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Discrete discontinuities exist between spatial scales, and at certain phase transitions, which defy theoretical explanation. The gap between the quantum and classical worlds, and the energetic path to superconductivity, are exemplary illustrations of inscrutable seams in the fabric of existence.
