Current students

The number theory of quantum information

Jon Yard, IQC

Abstract: Quantum-mechanical amplitudes and unitaries are typically expressed over the complex numbers. Because there is a continuum of complex numbers, classical computations of quantum systems generally utilize finite-precision approximations by rational numbers.

Dagmar Bruss, University of Duesseldorf

The resource theory of quantum coherence studies the off-diagonal elements of a density matrix in a distinguished basis, whereas the resource theory of purity studies all deviations from the maximally mixed state. We establish a direct connection between the two resource theories, by identifying purity as the maximal coherence, which is achievable by unitary operations. The states that saturate this maximum identify a universal family of maximally coherent mixed states.

The Creative Destruction Lab (CDL) is hosting a half-day symposium to discuss recent advances in Quantum Machine Learning, its near-term industry applications, and opportunities for commercialization with private financing as a technology startup.

Crystal Senko: Ion traps and multi-level quantum systems

I give an overview of trapped ion quantum information experiments and discuss prospects for implementing multi-valued quantum logic using trapped ions.

Jan Haase, Universität Ulm

Whenever one is tempted to employ a quantum system for any kind of applications, the focus usually lies on two properties setting it apart from a system described by a classical theory, namely the coherent superposition of different quantum states and entanglement between two ore more constituents forming the system.

M.Sc. Thesis Presentation

Candidate: Hyeran Kong

PhD Seminar

Chunhao Wang, PhD candidate

David R. Cheriton School of Computer Science

We give a dissipative quantum search algorithm that is based on a novel dissipative query model. If there are $N$ items and $M$ of them are marked, this algorithm performs a fixed-point quantum search using $O(\sqrt{N/M}\log(1/\epsilon))$ queries with error bounded by $\epsilon$. In addition, we present a continuous-time version of this algorithm in terms of Lindblad evolution.

PhD Seminar

Chunhao Wang, PhD candidate

David R. Cheriton School of Computer Science

We present a quantum algorithm for simulating the dynamics of Hamiltonians that are not necessarily sparse. Our algorithm is based on the assumption that the entries of the Hamiltonian are stored in a data structure that allows for the efficient preparation of states that encode the rows of the Hamiltonian. We use a linear combination of quantum walks to achieve a poly-logarithmic dependence on the precision.