SciPost Phys. 13, 039 (2022) ·
published 30 August 2022
|
· pdf
We address a subject that could have been analyzed century ago: how does the
universe of general relativity look like when it would have been filled with
solid matter? Solids break spontaneously the translations and rotations of
space itself. Only rather recently it was realized in various context that the
order parameter of the solid has a relation to Einsteins dynamical space time
which is similar to the role of a Higgs field in a Yang-Mills gauge theory.
Such a "crystal gravity" is therefore like the Higgs phase of gravity. The
usual Higgs phases are characterized by a special phenomenology. A case in
point is superconductivity exhibiting phenomena like the Type II phase,
characterized by the emergence of an Abrikosov lattice of quantized magnetic
fluxes absorbing the external magnetic field. What to expect in the
gravitational setting? The theory of elasticity is the universal effective
field theory associated with the breaking of space translations and rotations
having a similar status as the phase action describing a neutral superfluid. A
geometrical formulation appeared in its long history, similar in structure to
general relativity, which greatly facilitates the marriage of both theories.
With as main limitation that we focus entirely on stationary circumstances --
the dynamical theory is greatly complicated by the lack of Lorentz invariance
-- we will present a first exploration of a remarkably rich and often simple
physics of "Higgsed gravity".
SciPost Phys. 6, 061 (2019) ·
published 20 May 2019
|
· pdf
Could it be that the matter from the electrons in high Tc superconductors is
of a radically new kind that may be called "many body entangled compressible
quantum matter"? Much of this text is intended as an easy to read tutorial,
explaining recent theoretical advances that have been unfolding at the cross
roads of condensed matter- and string theory, black hole physics as well as
quantum information theory. These developments suggest that the physics of such
matter may be governed by surprisingly simple principles. My real objective is
to present an experimental strategy to test critically whether these principles
are actually at work, revolving around the famous linear resistivity
characterizing the strange metal phase. The theory suggests a very simple
explanation of this "unreasonably simple" behavior that is actually directly
linked to remarkable results from the study of the quark gluon plasma formed at
the heavy ion colliders: the "fast hydrodynamization" and the "minimal
viscosity". This leads to high quality predictions for experiment: the momentum
relaxation rate governing the resistivity relates directly to the electronic
entropy, while at low temperatures the electron fluid should become unviscous
to a degree that turbulent flows can develop even on the nanometre scale.
Prof. Zaanen: "This referee report signals th..."
in Submissions | report on Planckian dissipation, minimal viscosity and the transport in cuprate strange metals