## Department of Physics

### Department News

### Graduate Seminar on May 1

**Apr 30, 2012**

*******Seminar Announcement*****
PHYS600 Tuesday, May 1, 1:00 - 2:40 pm
Currens Hall 336
All physics faculty and students are invited.
Speaker: Kamal Chapagain
Graduate Student, Physics Department, WIU
Title: Universality of Arbitrary Quantum Logic Gate
Abstract:**

Time evolution of a quantum system is governed by a unitary operation given by the exponential of the Hamiltonian of the system. In the field of quantum information the goal is to obtain a certain output state as a desired result mathematically described through a certain unitary operation on the initial quantum state of the system. In general, any complicated unitary operator can be decomposed into set of simple unitary operators (quantum logic gates) that are physically easy to realize in the given quantum system. Here we want to show that any quantum logic gate is universal.

**Speaker: Mahdy H Almataawha**

Title: Refractive Index and Density Measurements in Bismuth Borate Glasses

Abstract:

Title: Refractive Index and Density Measurements in Bismuth Borate Glasses

Abstract:

We prepared a group of bismuth borate glasses by varying the bismuth oxide composition in the range 30-60 mol% and studied the variation of the refractive index and density as a function of glass composition. Glass samples were prepared using the melt quench method and annealed at temperatures near the glass transition for 3 hours to remove thermal strains. Annealed glass pieces were polished using an Inland Swap lap machine. We used a Brewster angle set up to measure the refractive index and Archimedes' method to measure the density. In general, bismuth borate glasses show higher refractive indices compared to other borate glasses (for example, lead borate). Refractive index values calculated from the atomic polarizabilities are smaller than the experimental values. Glass densities do show the expected dependence on composition.