## Summer Student Seminar

**Note:**Pizza will be served at 11:50am.

**Speaker:**JJ Oon (CME) and Xiangyi Meng (CMT)

**When:**August 29, 2019 (Thu), 12:00PM to 01:00PM (add to my calendar)

**Location:**SCI 352

**Hosted by:**Eric Boyers

*This event is part of the Graduate Student Council Events. *

JJ Oon (CME)

NV Centers for Magnetic Sensing Applications

The Nitrogen-Vacancy (NV) center is an atom-like defect within diamond that has been studied over the recent decades for reasons including their long decoherence times and spin-dependent optical properties. Additionally, their strong sensitivities to electromagnetic fields have given birth to numerous applications in precision sensing. In this talk we discuss how magnetic fields are measured using these defects, and the results of simulations over this summer.

Xiangyi Meng (CMT)

From Series/Parallel Rules to Zamolodchikov's c-Theorem

In this talk I will show that non-trivial series/parallel rules exist in studying how to optimize entanglement transmission in quantum networks (QN). These rules allow us to build a new statistical theory, which shares analogy with classical percolation theory but roots in a fundamental measure of entanglement, namely, concurrence. We find that this concurrence percolation theory (ConPT) belongs to a new universality class that differs from its classical counterpart. I will discuss how to generalize ConPT by g-concurrence, a geometric entanglement measure for any-dimensional bipartite systems. Such a generalization reveals a deeper connection between 1-D QN and the matrix product state (MPS), the latter of which is capable of representing most ground states faithfully because of its area-law nature in entanglement entropy. By studying (1+1) conformal field theory and Zamolodchikov's c-theorem it has been noticed that entanglement decreases both under local operations and classical communications (LOCC) and along renormalization group (RG) flows, the two of which, I will show, are indeed equivalent under a specific RG scheme on MPS/QN.