Condensed concepts

In February 1986, Bednorz and Müller made a stunning discovery: superconductivity at a temperature of 35 K in a doped copper oxide (cuprate)...

For an experimentalist one of the "easiest" quantities to measure for a metal is the electrical resistivity. Yet, for a many-body ...

Alejandro Mezio and I just posted a preprint Orbital-selective bad metals due to Hund’s rule and orbital anisotropy: a finite-temperature s...

There is a nice paper Bad metallic transport in a cold atom Fermi-Hubbard system  Peter T. Brown, Debayan Mitra, Elmer Guardado-Sanchez, R...

The BCS theory of superconductivity is one of the towering intellectual achievements of the twentieth century. There are many ingredients to...

An important and fascinating issue in many-body physics is the emergence of new energy scales, particularly scales that are orders of magni...

A definitive experimental signature of the crossover from a Fermi liquid metal to a bad metal is the disappearance of a Drude peak in the op...

One of most interesting new ideas about quantum matter from the last decade is that of a Hund's metal. This is a strongly correlated met...

Update. 14 Jan. 2026. I just learned that the paper discussed in this post was retracted last year. "following concerns raised about th...

It is fun to come up with clever names for new physical phenomena: quark, big bang, Janus , slepton,  chromodynamics, inflation,  squashon, ...

There is an interesting preprint Viscosity Bound Violation in Viscoelastic Fermi Liquids   Matthew P. Gochan, Hua Li, Kevin S. Bedell Th...

A central concept of quantum-many body theory is that of coherent quasi-particles. Their key property is a well-defined relationship between...

The past two decades have seen impressive advances in Angle-Resolved PhotoEmission Spectroscopy (ARPES). This technique has played a particu...

In the metallic state of many strongly correlated electron materials, Fermi liquid properties are only observed at relatively low temperatur...

Today I am giving a talk in the Applied Physics Department at Stanford. My host is Sri Raghu . Here is the current version of the slides. ...

In 2011 it was proposed that pyrochlore iridates (such as Y2Ir2O7) could exhibit the properties of a Weyl semi-metal, the three-dimensional ...

After yesterday's colloquium a large group of IISER students (both undergraduate and graduate) expressed an interest in having a tutor...

Today I am giving a  seminar  at the  Institute of Physics in Belgrade . My host is  Darko Tanaskovic  who has done  nice work using DMFT t...

Last week in Ljubljana, I had a nice discussion with Denis Arčon about this paper concerning fullerenes, A3C60 where A = alkali metal. Opt...

Tomorrow I am giving a seminar on the absence of quantum limits to the shear viscosity in the Theoretical Physics department at the Stefan I...