#### IMSc Webinar

#### Neutral Excitations of Quantum Hall States: a Density Matrix Renormalization Group Study

#### Prashant Kumar,Department of Physics, Princeton University

*We use the dynamical structure factors of the quantum Hall states*

at $

u=1/3$ and $

u=1/2$ to study their excitation spectrum. Using the

density matrix renormalization group in combination with the time-dependent

variational principle on an infinite cylinder geometry, we extract the low

energy properties. At $

u=1/3$, a sharp magnetoroton mode and the

two-roton continuum agree with the fractionally charged quasi-particles

picture. At $

u=1/2$, we find low energy modes with linear dispersion and

the static structure factor $\bar s(q) \sim (q\ell)^3$ in the limit $q\ell

\rightarrow 0$. The properties of these modes can be explained by a

quasi-1D composite-fermion theory.

Here is the link to the Google meet:

meet.google.com/jnr-yfsk-mvu

Done