# Institut Transdisciplinaire d'Information Quantique (INTRIQ)

### Meeting de l'INTRIQ (Septembre 2010)

**1 Rue Belvédère Sud
Sherbrooke
**

**Meeting de l'INTRIQ (16-17 septembre 2010)**

**Location**

**Program**

**Thursday, September 16th**

LOCATION: **Eastside room**

8h30 - 9h15 Registration & breakfast served in conference room 9h20 - 9 h30 Opening remarks

9h30 - 10h00

**Guillaume Gervais,**

*Non-abelian electronics*

10h00 - 10h30

**Thomas Szkopek**,

*Weak Localization Studies of Large Area Graphene*

10h30 - 11h00 Coffee break

11h00 - 12h00 **Hector Bombin, invited speaker**, *Anyons, twists and topological code*

**Ghislain Granger, invited speaker**,

*Coherent spin manipulation in a triple quantum dot*

**Coffee break**

**Louis Salvail**,

*Secure two-party quantum evaluation of unitaries against specious adversaries*

16h45 - 19h00

**Poster Session**with refreshments. Location: Midtown room.

19h30 **Dinner **(Auguste restaurant)

**Friday 17th,**

**September 2010**

**Business meeting**in Washington conference room, members only.

**Eastside room**

**William A. Coish, invited speaker**,

*Decoherence in ion-trap quantum registers and quantum-enhanced precision measurement*

**Nicolas Godbout,**

*Business Case for Quantum Information*

**Alexandre Blais**,

*Quantum information processing with superconducting qubits*

**Bertrand Reulet**,

*High frequency third cumulant of current noise : existence of quantum correlations in the zero-point fluctuations of electrons*

**Marcus Da Silva**,

*Efficient characterization of quantum states and processes*

**David Poulin**,

*The physics of quantum error correction*

**Michael Hilke**,

*Quantum error correction in a charge qubit quantum computer*

**Closing**and

**departure**

**Invited speakers**

*Hector Bombin*

**Anyons, twists and topological codes**

*William A. Coish*

**Decoherence in ion-trap quantum registers and quantum-enhanced precision measurement**

*Ghislain Granger*

Institute for Microstructural Sciences

National Research Council Canada

**Coherent spin manipulation in a triple quantum dot**

*Bertrand Reulet*

Université de Sherbrooke.

**High frequency third cumulant of current noise : existence of quantum correlations in the zero-point fluctuations of electrons**

**Speakers**

*Michael Hilke*

**Quantum error correction in a charge qubit quantum computer**

*Guillaume Gervais*

McGill University**Non-abelian Electronics**It is well-established that as the size of transistor and devices is reduced towards the nanoscale new quantum effects emerge that are for the most part a nuisance from the point-of-view engineering.

Here, we shall discuss the richness of the quantum physics that is likely to exist in extremely pure semiconductor-based devices, and in particular the link between quantum statistics, fractional quantum Hall liquids and topological quantum computation will be discussed.

Experiments that are underway and designed to uncover this physics will be presented.

*Thomas Szkopek*

McGill University

**Weak Localization Studies of Large Area Graphene**

Graphene is a 2D material of potential interest to implementing quantum information processing in the solid state. Large area graphene can be produced by epitaxial growth techniques on SiC and transition metals.

We report magneto-transport experiments on large area graphene. Weak-localization has been observed and fit to the theory of McCann et al. to extract electron scattering rates.

Preliminary work on the effect of molecular adsorbates on graphene conduction is presented, as is ongoing work to modify the electronic properties of graphene via exposure to atomic hydrogen.

*Louis Salvail*

**Université de Montréal**

**Secure Two-Party Quantum Evaluation of Unitaries Against Specious Adversaries**We describe how any two-party quantum computation, specified by a unitary which simultaneously acts on the registers of both parties, can be privately implemented against a quantum version of classical semi-honest adversaries that we call specious. Our construction requires two ideal functionalities to garantee privacy: a private SWAP between registers held by the two parties and a classical private AND-box equivalent to oblivious transfer. If the unitary to be evaluated is in the Clifford group then only one call to SWAP is required for privacy. On the other hand, any unitary not in the Clifford group requires one call to an AND-box per R-gate in the circuit. Since SWAP is itself in the Clifford group, this functionality is universal for the private evaluation of any unitary in that group.

SWAP can be built from a classical bit commitment scheme or an AND-box but an AND-box cannot be constructed from SWAP. It follows that unitaries in the Clifford group are to some extent the easy ones. We also show that SWAP cannot be implemented privately in the bare model.

*A**lexandre Blais*Université de Sherbrooke

**Quantum information processing with superconducting qubits**

*David Poulin*

Université de Sherbrooke

**The physics of quantum error correction**

*Richard MacKenzie*Université de Montréal

**Optimizing adiabaticity in quantum mechanics**

I will describe a recent effort to address the following question: Given a quantum mechanical system with a Hamiltonian depending on a number of time-dependent parameters, what evolution between given initial and final Hamiltonians (with fixed total time of evolution) maximizes the extent to which the evolution is adiabatic?

**POSTER SESSION**

*Jamie Gardner*Student, McGill university

Director: Aashish Clerk

**Damping of a mechanical oscillator coupled to a double quantum dot**

*Carolyn Young*

Student, McGill university

Director: Aashish Clerk

**Heisenberg Backaction in Quantum Point Contact Qubit Detectors**

*Benjamin Schmidt*Student, McGill university

Director: Guillaume Gervais

**Non-Abelian Electronics**

*Leonhard Benno Salwey***S**tudent, Université de Montréal

Directors: Gilles Brassard & Alain Tapp

**Classification of multi-partite entanglement in terms of permutation symmetries**

*David Roy-Guay*

**Student, Université de Sherbrooke**

Directors: Michel Pioro-Ladrière & Denis Morris

**Spin manipulation of NV centers in diamond**

*Maxime Boissonneault***S**tudent, Université de Sherbrooke

Director: Alexandre Blais

**Fourth order dispersive regime of circuit QED with a transmon and a CJBA**

*Julien Camirand Lemyre*Student, Université de Sherbrooke

Director: Michel Pioro-Ladrière

**Ultra-fast single-spin rotations based on the exchange interaction**

[1] W. A. Coish and D. Loss, Phys. Rev. B 75, 161302(R) (2007).

*Félix Beaudoin*Student, Université de Sherbrooke

Director: Alexandre Blais

**Spectroscopy of a superconducting qubit ultra-strongly coupled to an electromagnetic resonator**

*Guillaume Duclos-Cianci*Sstudent, Université de Sherbrooke

Director: David Poulin

**"Decoders for Topological Quantum Codes."**

*Olivier Landon-Cardinal*Student, Université de Sherbrooke

Director: David Poulin

**Efficient Direct Tomography for Matrix Product States**

*Jonathan Guillemette*

Student, McGill University

Director: Thomas Szkopek

**Weak Localization in Graphene on SiC and Graphene Grown on Copper**

*Eliot Bolduc*Student, Polytechnique de Montréal

Director: Nicolas Godbout &Suzanne Lacroix

**Detection electronics for single photon counting and gating**