[quantum-info] Room change: Two theory seminars at IQC next week

[Ashwin Nayak]

The IQC colloquium by Sergey Bravyi on Monday will be held in QNC 1501 
instead, due to the IPCO conference.

Best,
Ashwin


On Thu, 22 Jun 2017, Ashwin Nayak wrote:

>
> Dear colleagues,
>
> We have two theory seminars coming up next week, that may be of interest to 
> you:
>
> Monday, June 26, 2017, 2:30--3:30 pm, QNC 0101
> Complexity of quantum impurity models
> Sergey Bravyi, IBM TJ Watson
>
> Tuesday, June 27, 2017, 2--3 pm, QNC 1201
> Constraint Propagation Games
> Zhengfeng Ji, University of Technology, Sydney
>
> The abstracts are included below.
>
> Best,
> Ashwin
> --
>
> Monday, June 26, 2017, QNC 0101
> Complexity of quantum impurity models
> Sergey Bravyi, IBM TJ Watson
>
> I will discuss classical and quantum algorithms for simulation of quantum
> impurity models. Such models describe a bath of free fermions coupled to a
> small interacting subsystem called an impurity. Hamiltonians of this form
> were famously studied by Anderson, Kondo, Wilson and others in 1960s. More
> recently, impurity models found applications in DMFT simulations of
> strongly correlated fermionic systems. In this talk I will show that under
> very mild technical conditions ground states of impurity models can be
> efficiently prepared on a quantum computer. I will also describe a
> classical algorithm for approximating the ground energy of impurity models.
> The running time of our algorithm is polynomial in the system size and
> quasi-polynomial in the inverse approximation error. To arrive at these
> results we prove a general theorem characterizing correlations in the
> ground states of impurity models.
>
> Based on a joint work with David Gosset
>
>
>
>
> Tuesday, June 27, 2017, 2--3 pm, QNC 1201
> Constraint Propagation Games
> Zhengfeng Ji, University of Technology, Sydney
>
> Constraint propagation games are simple extended nonlocal games that are
> motivated by the propagation checking of quantum computation and have
> found powerful applications in the study of quantum proof systems
> recently. In this talk, we will introduce their definitions and basic
> properties, demonstrate their uses in larger games as building blocks,
> and illustrate the method that turns them into nonlocal games. Time
> permitted, we will briefly discuss their advantage in establishing
> rigidity properties and how they play a crucial role in showing that
> quantum multi-prover interactive proof systems can be compressed to
> nonlocal games with logarithmic message sizes.
>
>