School of Physics Spring Colloquium Series- Dr. Subir Sachdev

Dr. Subir Sachdev(Harvard) Many-fermion quantum entanglement in the cuprate superconductors.

Speaker: Dr. Subir Sachdev

Host: Zhu-Xi Luo

Title: Many-fermion quantum entanglement in the cuprate superconductors.

Abstract: Soon after the discovery of the cuprate high-temperature superconductors, P. W. Anderson suggested in 1987 that their physics is connected to insulators in which the spins of stationary electrons are highly quantum-entangled. Much theoretical progress has been made in understanding such insulating states with many-boson (i.e. spin) entanglement since then.

However, superconductivity requires mobile fermionic electrons, and I will describe the theory of two classes of quantum states with many-mobile-fermion entanglement. 
(A) the Fractionalized Fermi liquid (FL*), which was predicted to have properties consistent with recent angle-dependent magnetoresistance (ADMR) experiments on the under-hole-doped cuprate superconductors;
(B) the Sachdev-Ye-Kitaev model, and its impact on the theory of the strange metal phase of the cuprates. I will also briefly note the impact of the SYK model on the theory of charged black holes in asymptotically flat 3+1 dimensional space.

 

Bio: Subir Sachdev is Herchel Smith Professor of Physics at Harvard University. He has been elected to national academies of science in India and the US, and the Royal Society in the U.K. He is a recipient of several awards, including the Dirac Medal from the International Centre for Theoretical Physics, and the Lars Onsager Prize from the American Physical Society.

Sachdev has made extensive contributions to the theory of the diverse varieties of states of quantum matter, and of their behavior near quantum phase transitions. 

 

Event Details

Date/Time:

  • Date: 
    Monday, March 2, 2026 - 3:30pm to 4:30pm

Location:
 Marcus Nanotechnology 1116-1118