When: Tomorrow April 26 from 10:30 to 11:30 AM
Where: Cabot Division Room at Mallinckrodt
What: David is defending his thesis:
Time-Dependent Density Functional Theory for Open Quantum Systems and
Quantum Computation
First-principles electronic structure theory explains properties of atoms,
molecules and
solids from underlying physical principles without input from empirical
parameters. Time-dependent
density functional theory (TDDFT) has emerged as arguably the most widely
used first-principles method for describing the time-dependent quantum
mechanics of many electron
systems. In this talk, we will discuss how the fundamental principles of
TDDFT
can be extended and applied in two novel directions: The theory of open
quantum systems
(OQS) and quantum computation (QC).
In the first part of the talk, we will prove theorems that establish the
foundations
of TDDFT for open quantum systems (OQS-TDDFT). OQS-TDDFT allows for a first
principles
description of non-equilibrium systems, in which the electronic degrees of
freedom
undergo relaxation and decoherence due to coupling with a thermal
environment, such as a
vibrational or photon bath. We will then discuss density functionals in
OQS-TDDFT and
investigate their properties using an exactly solvable model system.
In the second part of the talk, we prove that the theorems of TDDFT can be
extended to a class of qubit Hamiltonians that are universal for quantum
computation. TDDFT applied to universal Hamiltonians implies that
single-qubit expectation values can be used as the basic variables in
quantum computation and information theory, rather than wavefunctions. We
will then explore some of the interesting implications of TDDFT for quantum
simulation using numerical examples.
--
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