We study the effect of nematic quantum critical fluctuations on quasiparticle interference. We show that nematic quantum critical fluctuations, which cause back and forth slushing of the d -wave nodes along the underlying Fermi surface, provide a natural mechanism for the accumulation of coherence that has been present in QPI experiments. © 2010 The American Physical Society.

We study the interplay between charge and spin ordering in electronic liquid crystalline states with a particular emphasis on fluctuating spin stripe phenomena observed in recent neutron scattering experiments. Based on a phenomenological model, we propose that charge nematic ordering is indeed behind the formation of temperature dependent incommensurate inelastic peaks near wave vector (π, π) in the dynamic structure factor of YBa2Cu3O6+y. We strengthen this claim by providing a compelling fit to the experimental data. © 2010 The American Physical Society.

This chapter is a progress report on the challenging yet promising frontier of quantum phase transitions (QPTs) in strongly correlated systems from the perspective of modern local probes and recent theoretical developments. The focus will be on our latest developments at this frontier. An outlook based on opportunities and questions emerging from these latest developments concludes the discussion. © Taylor & Francis Group.

We study the character of an Ising nematic quantum phase transition deep inside a d -wave superconducting state with nodal quasiparticles in a two-dimensional tetragonal crystal. We find that, within a 1/N expansion, the transition is continuous. To leading order in 1/N, quantum fluctuations enhance the dispersion anisotropy of the nodal excitations and cause strong scattering, which critically broadens the quasiparticle (qp) peaks in the spectral function, except in a narrow wedge in momentum space near the Fermi surface where the qps remain sharp.