Events

Krysta Svore, Microsoft Research

Recently it has been shown that Repeat-Until-Success (RUS) circuits can approximate a given single-qubit unitary with an expected number of T gates of about 1/3 of what is required by optimal, deterministic, ancilla-free decompositions over the Clifford+T gate set. In this work, we introduce a more general and conceptually simpler circuit decomposition method that allows for synthesis into protocols that probabilistically implement quantum circuits over several universal gate sets including, but not restricted to, the Clifford+T gate set.

Xiaodi Wu, Massachusetts Institute of Technology

In this talk, I will present a stronger version of the Doherty-Parrilo-Spedalieri (DPS) hierarchy of approximations for the set of separable states. Unlike DPS, our hierarchy converges exactly at a finite number of rounds for any fixed input dimension. This yields an algorithm for separability testing which is singly exponential in dimension and poly-logarithmic in accuracy.

Prasanna Venkatesh, Asia Pacific Center for Theoretical Physics

In the first part of the talk I will focus on resonant tunneling and directed transport of ultracold atoms that are strongly coupled to an optical lattice inside a ring-cavity and to which an uniform bias force is applied. The bias force induces Bloch oscillations causing amplitude and phase modulation of the lattice which resonantly modifies the site-to-site tunneling. We show how different aspects of the transport such as the direction and magnitude can be simply controlled by changing the cavity detuning.

Leon Pintsov,  CEO SignitSure Inc, Chief Scientist Emeritus Pitney Bowes Inc

Legal documents are omnipresent and a subject to fraudulent manipulation. Important examples include mail, drug prescriptions, sin taxes, contracts, deeds and stock certificates. Cryptography is a powerful and convenient tool that can be used to protect documents against counterfeiting, alteration, duplication and other forms of manipulation. The act of creating cryptographically-secured information that is added to a document constitutes an event that is visibly evidenced on the document.

Dr. Carla Fehr holds the Wolfe Chair in Scientific and Technological Literacy in the Philosophy Department at the University of Waterloo. She conducts research on ways that diversity promotes innovation and excellence in science and technology. Dr.

Peter Zoller, University of Innsbruck

Starting with an overview of quantum simulation with cold atoms and ions, the talk will focus on two recent developments. We will first discuss quantum simulation of lattice gauge theories both from a condensed matter and a high energy physics point of view. The second topic is open system quantum simulation, in particular on chiral spin networks, their quantum dynamics and realization with quantum optical systems.

Lianao Wu, University of the Basque Country

Universidad del País Vasco / Euskal Herriko Unibertsitatea

We use a Feshbach projection-operator partitioning technique (PQ partitioning) to derive a closed one- component integro-differential equation. The resultant equation properly traces the footprint of the target state in quantum control theory. The physical significance of the derived dynamical equation is illustrated by both general analysis and concrete examples. We show that control can be realized by fast-changing external fields, even fast noises.

John Morton, University College London

Electron and nuclear spins of donors in silicon are promising candidates for representing quantum bits, with coherence times of up to 3 seconds for the electron spin [1], up to 3 minutes for the neutral donor nuclear spin [2], and 3 hours for the ionized donor nuclear spin [3]. Furthermore, single-shot readout of both the electron spin and nuclear spin have been demonstrated, with measurement fidelities of up to 99.8% [4].

Torsten Scholak, University of Toronto

Rydberg atoms are highly excited neutral atoms with exceptional properties. Not long ago, interest in Rydberg atoms was limited to their spectroscopic properties. However, in recent years, Rydberg science has become increasingly interdisciplinary. It is now a rapidly progressing research area at the crossroads of atomic, optical, condensed matter physics, and quantum information science with a host of possible applications.

Joel Wallman, IQC

Quantum computers are poised to deliver a dramatic increase in computational power, which can be used to perform difficult tasks such as simulating molecules for medical research much more efficiently than any current computer. However, it is notoriously difficult to characterize what is needed for a quantum computer to be useful. In this talk I will show that two characteristic quantum phenomena, namely, negative probabilities and contextuality, are equivalent with respect to the stabilizer formalism for qudits (d odd prime).