When: Today Friday April 13 from 2:30 to 3:30 PM
Where: Cabot Division Room at Mallinckrodt
What: Alejandro is defending:
"Designing and Probing Open Quantum Systems: Quantum Annealing,
Excitonic Energy Transfer, and Nonlinear Fluorescence Spectroscopy
Abstract
The 20th century saw the first revolution of quantum mechanics, setting the
rules for
our understanding of light, matter, and their interaction. The 21st century
is focused
on using these quantum mechanical laws to develop technologies which allows
us to
solve challenging practical problems. One of the directions is the use
quantum devices
which promise to surpass the best computers and best known classical
algorithms for
solving certain tasks. Crucial to the design of realistic devices and
technologies is to
account for the open nature of quantum systems and to cope with their
interactions
with the environment. In the first part of this dissertation, we show how
to tackle
classical optimization problems of interest in the physical sciences within
one of these
quantum computing paradigms, known as quantum annealing (QA). We present the
largest implementation of QA on a biophysical problem (six di↵erent
experiments
with up to 81 superconducting quantum bits). Although the cases presented
here
can be solved on a classical computer, we present the first implementation
of lattice
protein folding on a quantum device under the Miyazawa-Jernigan model. This
is
the first step towards studying optimization problems in biophysics and
statistical
mechanics using quantum devices.
In the second part of this dissertation, we focus on the problem of
excitonic energy
transfer. We provide an intuitive platform for engineering exciton transfer
dynamics
and we show that careful consideration of the properties of the environment
leads to
opportunities to engineer the transfer of an exciton. Since excitons in
nanostructures
are proposed for use in quantum information processing and artificial
photosynthetic
designs, our approach paves the way for engineering a wide range of desired
exciton dynamics.
Finally, we develop the theory for a two-dimensional electronic
spectroscopic
technique based on fluorescence (2DFS) and challenge previous theoretical
results
claiming its equivalence to the two-dimensional photon echo (2DPE)
technique which
is based on polarization. Experimental realization of this technique
confirms our theoretical
predictions. The new technique is more sensitive than 2DPE as a tool for
conformational determination of excitonically coupled chromophores and
o↵ers the
possibility of applying two-dimensional electronic spectroscopy to
single-molecules."
--
Joel Yuen-Zhou
PhD candidate in Chemical Physics
Harvard University CCB,
12 Oxford St. Mailbox 107,
Cambridge, MA, USA.
_______________________________________________
Aspuru-meetings-list mailing list
Aspuru-meetings-list(a)lists.fas.harvard.edu
https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list