Les activités de l'INTRIQ

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nov. 11, 2019

At Hotel Château Bromont

Organizers :
     Éva Dupont Ferrier, Université de Sherbrooke
     Dave Touchette, Université de Sherbrooke


90, rue Stanstead, Bromont QC J2L 1K6
Téléphone : 1 800 304 3433

Note : The INTRIQ Business meeting (reserved for members) will be held in room "Salle des cantons" on November 11th from 9h30 to 10h30

Registration
Carpooling
Chartered bus (Berri-Bromont-Berri)

mai 29, 2019

Colloque scientifique au congrès de l'Acfas, mercredi le 29 mai 2019

L’information quantique : avancées fondamentales et possibilités technologiques

Organisateurs :
     Professeure Anne Broadbent, Université d'Ottawa
     Professeur Stéphane Kéna-Cohen, Polytechnique Montréal

janv. 8, 2019

CONFETI (CONFérence ÉTudiante de l'INTRIQ) is a yearly student conference sponsored by the INTRIQ. It attracts graduate students and post-docs in the fields of physics, mathematics, computer science and engineering working on quantum computing related projects.

Where and when
The conference will take place on January 8-10, 2019 at the Hôtel Château Bromont in Bromont, Québec.

Schedule
Click here

Registration
Click here

 

Institut Transdisciplinaire d'Information Quantique (INTRIQ)

nov. 11, 2019
Posté par : Marc Leclair

Fall 2019 INTRIQ meeting, November 11th & 12th


At Hotel Château Bromont

Organizers :
     Éva Dupont Ferrier, Université de Sherbrooke
     Dave Touchette, Université de Sherbrooke


90, rue Stanstead, Bromont QC J2L 1K6
Téléphone : 1 800 304 3433

Note : The INTRIQ Business meeting (reserved for members) will be held in room "Salle des cantons" on November 11th from 9h30 to 10h30

Registration
Carpooling
Chartered bus (Berri-Bromont-Berri)

https://docs.google.com/spreadsheets/d/1DIzXXLxCNWOxp9qt6HUYE2MPCrgrZ9YAD3G2W8xY6gI/edit?usp=sharingPreliminary meeting program

November 11th

10h30 - 10h55  Registration

10h55 - 11h00  Opening remarks (Salon A)

11h00 - 12h00  Talks to be announced

12h00 - 13h30  Lunch  (Dining room - 4 Canards)

13h30 - 14h30  Talks to be announced

14h30 - 15h00  Industry : Startups in quantum 

15h00 - 15h30  Coffee break  (Salon B)

15h30 - 17h00  Talks to be announced

17h00 -             Poster session with refreshments (Salon B)

19h30 -             INTRIQ dinner (Knowlton room)

 

November 12th

  8h30 - 10h00  Talks to be announced

10h00 - 10h30  Coffee break (Salon B)

10h30 - 11h00  Equity Diversity Inclusion

11h00 - 12h00  Talks to be announced

12h00 - 13h30  Lunch  (Dining room - 4 Canards)

13h30 - 15h30  Talks to be announced

15h30 - 15h40  Closing remarks

Invited speakers
( More to be annouced )

Dr Tomas Jochym-O'Connor
IBM - Yorktown Heights, New York
Title and abstract to be annouced

Dr Signe Seidelin
Institut NEEL CNRS/UGA
Rare-Earth Doped Crystals for strain-coupled optomechanics
A challenge of modern physics is to investigate the quantum behavior of a bulk material object - for instance a mechanical oscillator - placed in a non-classical state. One major difficulty relies in interacting with the mechanical object without perturbing with its quantum behavior. An approach consists of exploiting a hybrid quantum system consisting of a mechanical oscillator coupled to an atom-like object, and interact via the atom-like object. A particularly appealing coupling mechanism between resonator and “atom” is based on material strain. Here, the oscillator is a bulk object containing an embedded artificial atom (dopant, quantum dot, ...) which is sensitive to mechanical strain of the surrounding material. Vibrations of the oscillator result in a time-varying strain field that modulates the energy levels of the embedded structure. We have suggested to use rare-earth doped crystals for strain-coupled systems [1] and proposed a mechanism to cool down the resonator [2]. In this talk, I will report on our progress towards realizing experimentally these protocols. We are using an yttrium silicate (Y2SiO5) crystal containing triply charged europium ions (Eu3+), which are optically active. The reason behind this choice stems from the extraordinary coherence properties of this dopant, combined with its high strain-sensitivity: the Eu3+ in an Y2SiO5 matrix has an optical transition with the narrowest linewidth known for a solid-state emitter, and the transition is directly sensitive to strain. We have successfully fabricated mechanical resonators, designed and set up the experiment, and achieved a signal-to-noise ratio compatible with the planned measurements, as well as measured the strain sensitivity of europium ions in bulk Y2SiO5 crystals.
[1] K. Mølmer, Y. Le Coq and S. Seidelin, Dispersive coupling between light and a rare-earth ion doped mechanical resonator, Phys. Rev. A 94, 053804 (2016)
[2] S. Seidelin, Y. Le Coq and K. Mølmer, Rapid cooling of a strain-coupled oscillator by an optical phase-shift measurement, Phys. Rev. A 100, 013828 (2019)

Poster session
( More to be annouced )

Sophie Berthelette
Doctorate, Université de Montréal
Director : Gilles Brassard
Title and abstract will be announced

Alexandre Choquette
Master, Université de Sherbrooke
Director : Alexandre Blais
Variational Quantum Algorithms for the Fermi-Hubbard model
Noisy intermediate-scale quantum computation has the potential to be useful for the simulation of quantum materials. A prominent simulation approach is using variational quantum algorithms (VQAs), which have some resilience to noise and can handle limited qubit connectivity. Here, we aim to simulate the Fermi-Hubbard-model ground state by means of a VQA. We investigate a number of possibilities for engineering the variational state-preparation circuit, and benchmark these in presence of realistic noise. We find that Hamiltonian-inspired variational forms have better performance over a hardware-efficient approach. This work is progress towards the simulation of high-Tc superconductivity on a quantum device.

Felix Fehse
Doctorate, McGill University
Director : William Coish
Title and abstract will be announced

Genki Fukuda
Master, National Research Council (NRC) - Ottawa
Director : Andrew Sachrajda
Fabrication and irradiation effects of field-induced shallow two-dimensional electron gas in dopant-etched modulation-doped GaAs/AlGaAs heterostructures
Collaboration with Takafumi Fujita, Yasushi Kanai, Kazuhiko Matsumoto, Yuji Sakai, Haruki Kiyama, Julian Ritzmann, Arne Ludwig, Andreas D. Wieck, and Akira Oiwa (Osaka University, Ruhr University Bochm).: Electron spin qubits based on GaAs/AlGaAs gate-defined quantum dots (QDs) formed in a two-dimensional electron gas (2DEG) are strong candidates for a single photon and single electron spin quantum interface. However, suppression of the irreversible response of photon irradiation in conventional doped GaAs/AlGaAs gate-defined QDs is indispensable for performing stable and continual manipulation of a single electron spin generated by a single photon. It is one of the most promising solution to utilize QDs formed in a field-induced 2DEG on undoped heterostructures since these problems are caused by Si dopants. On the other hand, it is necessary in conventional undoped structures to optimize complicated etching and deposition processes for fabrication of Ohmic contacts to avoid creating a discontinuous 2DEG and undesired leakage paths to the top gates. Here, we show the fabrication and irradiation effects of an improved field-induced 2DEG structure in dopant-etched modulation-doped GaAs/AlGaAs heterostructures taking advantage of a conventional doped structure to simplify ohmic contact fabrication. We successfully induce a 2DEG and evaluate the effects of the light irradiation on the transport properties while an electric current decays with time. This work may provide an additional way to realize undoped GaAs gate-defined QDs for robust quantum interface against photon irradiation.

Ioanna Kriekouki
Doctorate, Université de Sherbrooke
Director : Michel Pioro-Ladrière
28nm UTBB FD-SOI technology for Silicon-based quantum dots and cryo-CMOS electronics
Although  remarkable  progress  has  been  made  over  the  last  few  years  in  the  field  of Silicon-based  spin  qubits  hosted  in  small  scale  conventional CMOS technologies, coupling several qubits together for the needs of large-scale  logical  operations  remains  a  challenge.  Utilizing  state  of  the  art  mass  production process methods from the field of microelectronics seems to be a very promising candidate to solve this problem. Another problem that needs to be tackled concerns the control electronics for  the  qubits.  Indeed,  in  the  case  where  more  than  a  thousand  qubits  will  need  to  be controlled, the heat and noise produced by standard electronics will rapidly be a major issue.
Our goal towards a compact quantum processor is to develop a Silicon-based electron or  hole spin  qubit  architecture  fabricated  via  industrial  techniques,  with  on-chip  embedded control  achieved  by  co-integrating  classical  electronics  at  cryogenic  temperatures.  In  this poster, we present our progress on both the qubit architecture and the cryogenic electronics. Our  qubit  device  is  designed  and  fabricated  using  exclusively  CMOS  industrial manufacturing  techniques,  based  on  STMicroelectronics’  28nm  fully  depleted  silicon-on-insulator  (FD-SOI)  planar  ultra-thin  body  and  BOX  (UTBB)  technology. We  report  our progress  on  both  single and  multiple  quantum  dot  systems  in  1D  (array)  and  2D  (matrix) architectures.We  also  propose  a  design  for  cryogenic  CMOS  electronics  for  manipulation  and read-out  of  many  qubits,  in  order  to  perform  logical  operations  for  the  needs  of  large-scale quantum computing. FD-SOI is a promising technology for cryoCMOS implementation, as it has  already  been  demonstrated  to  operate  down  to  4K.  We  studied  the  performance  of ring oscillators, consisting of 28nm FD-SOI NMOS and PMOS transistors, designed to generate 6 to 10 GHz microwave signals.Our ring oscillator is coupled to a frequency divider, enabling on-chip down-conversion, allowing readout with conventional electronics measurement setup in the MHz regime.

Zoé McIntyre
Master, McGill University
Director : William Coish
Title and abstract will be announced

Tomohiro Nakagawa
Doctorate, National Research Council (NRC) - Ottawa
Director : Andrew Sachrajda
Formation of quantum dots on (110) GaAs substrate
Collaboration with Rio Fukai, Yuji Sakai, Takafumi Fujita, Haruki Kiyama, Takashi Nakajima, Julian Ritzmann, Arne Ludwig, Andreas D. Wieck, Seigo Tarucha, and Akira Oiwa (Osaka University, Ruhr University Bochm, RIKEN, and University of Tokyo).: Gate-defined semiconductor devices provide a platform which enable us to perform various quantum transport experiments. Electron spins in gate-defined GaAs quantum dots (QDs) have been extensively studied for integrated and stable quantum bits. In those experiments, epitaxial layers grown on the (001) plane are generally used. In a (110) GaAs quantum well (QW), we expect more efficient photon-electron spin quantum state conversion by exciting heavy-hole Zeeman levels under in-plane magnetic field. However, experimental works on the electrically-defined low dimensional systems on the (110) substrate have been hardly done. From the Hall bar measurements, the mobility and electron density of a QW grown on (110) substrate were estimated as 7×104 cm2/Vs and 9×1010 cm-2, respectively at a temperature of 1.5 K. Subsequently, we fabricated gate-defined lateral QDs and measured them using a dilution refrigerator. We clearly observe Coulomb oscillations in the few-electron regime by monitoring a nearby charge sensor current. We expect that the (110) GaAs QDs will provide a new platform for studying photon-spin coupling.

Anne-Laurence Phaneuf
Doctorate, Polytechnique Montréal
Director : Sébastien Francoeur
Exciton-Polaritons as a tool to control the emission characteristics of excitons and trions bound to Te2 in ZnSe
Te2 molecules in ZnSe form a quantum defect that offers advantageous characteristics, including a high optical uniformity due to its atomic nature and a strong optical dipole moment matching those from semiconductor nanostructures, for the development of efficient spin-photon interfaces for applications in quantum optics, communications and networks.
In this work, we demonstrate that excitons-polaritons generated in the ZnSe host material can be used to deterministically control the emission characteristics of excitons and trions bound to a single Te2 molecule. In particular, the emission efficiency is increased by two orders of magnitude, indicating a very efficient coupling between free excitons and Te2 bound states.
Scanning the free-exciton band with a narrow-frequency tunable laser over the free exciton spectral region reveals strong in-phase oscillations with a period of about 1 meV in the bound exciton emission intensity, emission energy, and emission linewidth. These modulations are explained by the strong coupling naturally occurring in ZnSe between photons and free-excitons, or exciton-polaritons.
This type of cooperative process whereby a host excitation is used to control the behavior of a single emitter has never been reported before. It allows deterministically controlling the emission properties and enables the development of new coherent control schemes.

Pericles Philippopoulos
Doctorate, McGill University
Director : William Coish
Title and abstract will be announced

Mathias Pont
Master, Polytechnique Montréal
Director : Sébastien Francoeur
Title and abstract will be announced

Claude Rohrbacher
Doctorate, Université de Sherbrooke
Director : Eva Dupont-Ferrier
High-resolution cryogenic capacitance measurements of FD-SOI structures using a capacitance bridge 
As CMOS structures are envisioned to host silicon spin qubits and for co-integrating quantum systems with control electronics, the cryogenic behaviour of such structures must be investigated. Capacitance-voltage (CV) measurements are widely used to determine semiconductor parameters. Performing high-resolution CV measurements at cryogenic temperatures is necessary to characterize CMOS structures and can set a path towards charge readout of quantum dots based on capacitance change. However, in nanoscale devices the capacitance to be measured is often reduced to hundreds of  attofarads. Moreover, the wiring of dilution fridges introduces lengths of cables that have a parasitic capacitance on the order of nanofarads, hindering such measurements. Here we present a highly sensitive capacitance bridge circuit designed to perform measurements inside a dilution refrigerator with attofarad resolution. We demonstrate the utility of our circuit by performing split C-V measurements on 28 nm Fully Depleted Silicon on Insulator (FD-SOI) nanostructures at 20 mK. Preliminary results also show that Coulomb blockade is observable using this method; a first step towards charge readout using a capacitance bridge.

Marc-Antoine Roux
Master, Université de Sherbrooke
Director : Michel Pioro-Ladrière
Fast tuning of quantum dots using FPGAs
Spin qubits are a promising architecture for quantum computers due to their long coherence time and compatibility with industrial fabrication techniques. However, scalability issues arise when trying to create a system with many qubits. The more qubits there are, the more time it takes to initialize the system in the desired configuration and the more equipment is needed to control each quantum dot. Therefore, a scalable qubit control system addressing both these issues is presented. By using a Field Programmable Gate Array (FPGA) based system, it is possible to greatly accelerate device characterization while being relatively compact. The FPGA system can be several orders of magnitude faster than typical apparatus allowing for real-time measurements.

Sara Turcotte
Master, Université de Sherbrooke
Director : Michel Pioro-Ladrière
Title and abstract will be announced

 

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