## Free-space Polarization-selective Microcavity based on Chiral Metasurfaces

Summary Developing a new type of Fabry-Pérot cavity that allows improved control of the atoms’ emission into the cavity mode will result in enhancement of the efficiency and fidelity of quantum state transfer from photons to atoms and back. This in turn can be used to improve the performance of quantum networks and repeaters, as […]

septembre 19, 2019

## Entangled Photon Orbital Angular Momentum Arrays

Summary Arrays of orbital angular momentum (OAM) states of light are a new form of structured light so far relatively unexplored in quantum information science. Unlike spin angular momentum of light, which is related to light’s polarization and covers two dimensions, OAM states, sometimes described as ‘donut beams’ due to the shape of the field […]

septembre 19, 2019

## Line-Scanning optical coherence tomography system for in-vivo, non-invasive imaging of the cellular structure and blood perfusion of biological tissue

Summary Optical coherence tomography (OCT) is an optical imaging method that allows for in-vivo, non-invasive imaging of the structure and vasculature of biological tissue. Commercially available, clinical OCT systems utilize point-scanning method to acquire volumetric images over a large surface with typical frame rates of ~ 30 frames/ second. Since living biological tissue is constantly […]

août 27, 2019

## Novel Superconducting Qubits for Error-Corrected Processors

Summary In this project, we develop novel superconducting qubits for error-corrected processors to enable large-scale quantum computing. Our design efforts will specifically target error-corrected architectures through a variety of paths. Possible features will include built-in parity measurements and the use of bosonic codes, such as Fock state and Cat codes, as our starting focus. Early […]

juin 26, 2019

## Quantum Simulations of Fundamental Interactions

Summary To address questions in modern physics such as “what is the structure of matter inside neutron stars?” we need better computational methods to evaluate the interplay of fundamental forces between elementary particles. To-date the response to such questions rests on numerical computer simulations that are inherently limited. In this project, we develop new theoretical […]

avril 18, 2019

## Quantum Computational Resources in the Presence of Symmetry

Summary Fault-tolerance is essential to the performance of quantum technologies, but known schemes are extremely resource intensive. Thus, improving existing schemes or inventing new schemes is of central importance. This joint project is based on the realization that fault-tolerance schemes make use of symmetries in fundamental ways, and that studying the problem of fault tolerance […]

mars 13, 2019

## Combined momentum- and real-space photoelectric probes of dimensionality-tuned Weyl semimetals

Summary The library of two-dimensional (2D) materials has recently grown to include topological insulators and semimetals. Their incorporation in special device geometries may lead to novel quantum electronics with enhanced functionalities. Weyl semimetals, in particular, offer the most robust form of topological protection. Recent results from our group indicate that Weyl nodes should be […]

mars 12, 2019

## Zero-Dimensional Quantum Materials for the Next Generation of Highly-Selective Chemical Sensors

Summary Heavy metals are a major public health concern and their on-site detection in water supplies is not well served by existing lab techniques. We develop a new multi-modal platform comprising functionalized quantum dots of two-dimensional materials (2D-QDs) for the sensing of four highly-toxic heavy metal pollutants (arsenic, cadmium, lead and mercury). The zero-dimensional […]

mars 11, 2019

## Scanning Tunneling Microscopy of Quantum Materials, Devices and Molecules

Summary This project advances our ability to characterize and study novel quantum materials, quantum devices, and even individual molecules at the atomic level. By combining Non-Contact Atomic Force Microscopy (NC-AFM), Scanning Tunneling Microscopy (STM) and scanning gate methods, we correlate spatial information with transport properties and can locally manipulate charge, spin and structural states. […]

janvier 28, 2019

## Materials for Majorana-based Topological Qubits

Summary Topological qubits offer a novel pathway to scalable quantum computing by simultaneously allowing for ease of coupling between qubits and strong decoupling of qubits from noise and dissipation. The most promising direction explores the topologically induced protection of theoretically predicted exotic quasiparticles, the so-called Majorana Zero Modes or MZMs. To-date MZMs, which follow […]

janvier 28, 2019

## Composite Superconductors for Improved Quantum Coherence

Summary Conventional superconductors have trouble performing well in magnetic fields required for electron spin resonance (ESR) – based quantum information processing applications. We can, however, use proximity engineering to select desired properties from different materials and combine them for improved superconducting performance in magnetic fields — an improvement that would have strong implications for […]

décembre 12, 2018

## Topological Properties of Exciton-Polaritons in a Kagome Lattice as a Solid-state Quantum Simulator

Summary In this project, we build a solid-state quantum simulator for engineering a specific Hamiltonian. Quantum simulators are purpose-built devices with little to no need for error correction, thereby making this type of hardware less demanding than universal quantum computers. Our platform consists of exciton-polariton condensates in multiple quantum-wells sandwiched in a semiconductor Bragg […]

décembre 8, 2018

## Hybrid Quantum Materials towards Topological Quantum Computing

Summary Proximity engineered hybrid materials have shown promise for topological quantum information processing. This form of quantum computing provides a stable, error-tolerant approach for building scalable quantum information processors. Topological quantum computing relies on braiding non-Abelian particles, such as Majorana fermions, which do not exist in nature. One can however use materials engineering to […]

décembre 8, 2018

## Quantum Sensing Applications using Quantum Communication Technology

Summary The Quantum Encryption and Science Satellite provides a platform to develop and deploy quantum sensing and metrology via photonic channels. This project will build upon ‘free-space’ quantum communication technology and explore new approaches and methods to advance two primary applications: quantum-enhanced telescopes, and spectroscopic sensing for methane detection in the atmosphere. For the […]

décembre 8, 2018

## Silicon Platform for Electron Spin Qubits

Summary Scaling solid-state quantum processors to a useful threshold while maintaining the requisite precision in quantum control remains a challenge. We propose a quantum metal-oxide-semiconductor (QMOS) architecture operating at cryogenic temperatures that is based on a network/node approach as a means to scalability. By working with QMOS, we benefit from the deep investments and […]

décembre 7, 2018

## Hybrid Quantum Repeater based on Atomic Quantum Memories and Telecom Wavelength Entangled Photon-Pairs Generated from Semiconductor Nanowires

Summary Losses in physical channels, such as optical fibres, limit existing quantum communication systems to modest distance ranges. Since amplification of quantum signals is fundamentally not possible, we look to extend the range and functionality of these quantum channels by adding quantum memory nodes that can daisy-chain multiple lengths of quantum channels through entanglement […]

octobre 29, 2018

## On-Chip Microwave-Optical Quantum Interface

Summary In this project we develop a quantum interface between microwave and optical photons as a key enabling technology of a hybrid quantum network. In such a network, the robust optical photons carry quantum information through optical fibres over long distances, while superconducting microwave circuits protected from thermal photon noise by the low temperature […]

octobre 29, 2018

## Chiral Quantum Antenna Based on Multilayer Metasurface

Summary Individual atoms can act as stationary qubits and thus serve as nodes in quantum computing networks or as memories for quantum repeaters. However, to successfully use qubits based on single atoms suspended in free space, photons emitted by a single atom need to be efficiently collected. Conventionally, this can be done with high […]

septembre 20, 2018

## Inverse Photoemission Spectroscopy of Quantum Materials

Summary Quantum materials that exhibit strong electron correlations lead to phenomena, such as superconductivity and topologically protected states, that are important for quantum computation, sensing, and other applications. For example, we may utilize symmetry protected topological states to make qubits that are robust against decoherence, while advances in high temperature superconductors may significantly reduce […]

septembre 20, 2018

## Spin-transfer Torque Magnetic Random Access Memory for On-chip Spin Information Storage

Summary Leakage power in semiconductor memories, such as Dynamic Random Access Memory (DRAM) and Static Random Access Memory (SRAM), can be substantial and is one of the limits for scalability of classical electronics. This is attributed to the fact that the information stored is volatile, requiring constant refreshing, as well as reprogramming upon powering […]

août 6, 2018

## Implementing High-fidelity Quantum Gates in Multi-level Trapped Ions

Summary The scalability of quantum processors is limited by current error rates for single-qubit gates. By encoding more than a single bit of information within a single ion, multi-level “qudits” offer a promising method of increasing the information density within a quantum processor, and therefore minimizing the number of gates and associated error rates. […]

juillet 30, 2018

## Engineering and Characterizing Programmable Interaction Graphs in a Trapped Ion Quantum Simulator

Summary Quantum simulators have the potential to bring unprecedented capabilities in areas such as the discovery of new materials and drugs. Engineering precise and programmable interaction graphs between qubits or spins forms the backbone of simulator applications. The trapped ion system is unique in that the interaction graph between qubits can be programmed, in […]

juillet 24, 2018

## Quantum Light Sources Based on Deterministic Photon Subtraction

Summary This project develops new sources of light that utilize quantum entanglement to enhance imaging resolution and detection. We aim to go beyond simple photon pairs and advance our understanding and control of new quantum states of light. Our approach uses deterministic single-photon subtraction (removing of a specific photon from a pulse of light) […]

juillet 13, 2018

## Ultrafast Dynamical Studies of Valley-Based Qubits

Summary As monolayers, transition metal dichalcogenides (TMDCs) – such as tungsten diselenide (WSe2) – become direct-bandgap semiconductors capable of emitting light. Compared to conventional direct-bandgap semiconductors, such as III-V semiconductors like GaAs, excitons (quasiparticles made of an electron hole bound with an electron) and single-layer TMDCs (SL-TMDCs) have much stronger binding energy. Excitons and […]

juin 29, 2018

## Cryo-CMOS to Control and Operate 2D Fault-Tolerant Qubit Network

Summary Large-scale, fault-tolerant quantum computation requires precise and stable control of individual qubits. This project will use complementary metal-oxide-semiconductor (CMOS) technology to provide a cost-effective scalable platform for reliable and high-density control infrastructure for silicon spin qubits. We will use sub-micron CMOS technology to address device and circuit-level challenges and explore the integration of […]

juin 14, 2018

## Harnessing the Promise of Quantum Materials for Future Electronic Devices

Summary Two-dimensional (2D) quantum materials, such as graphene and molybdenum disulfide, have great potential for use in future flexible and wearable electronics applications. With traditional silicon-based electronics nearing their theoretical performance limits, nano-electronics made from 2D quantum materials offer breakthrough opportunities for energy-efficient, wearable ubiquitous computation. In this project, we will study integration of […]

juin 14, 2018

## Quantum State Tomography with Machine Learning

Summary An important challenge in building a quantum computer is quantifying the level of control obtained in the preparation of a quantum state. The state of a quantum device is characterized from experimental measurements, using a procedure known as tomography. Exact tomography requires a vast amount of computer resources, making it prohibitive for quantum […]

juin 6, 2018

## Plasmon Control of Quantum States in Semiconductor Nanocrystals

Summary Thanks to the light-induced collective oscillations of free charges at the boundary between a conducting material and a dielectric, known as surface plasmon resonance, metallic nanostructures can exhibit strong light absorption and scattering. The sensitivity of these resonances to the local environment and shape of the metallic structures allows them to be used, […]

mars 21, 2018

## Developing Tools for Quantum Characterization and Validation

Summary Coherence is essential for quantum computation; yet it introduces a unique sensitivity to any imperfections in hardware design, control systems, and the operating environment. Overcoming these sensitivities requires a hierarchy of strategies, ranging from optimization of the hardware architecture to software solutions including quantum error correction. Randomized Benchmarking Protocols are an important family of […]

octobre 3, 2017

## Quantum Simulation of Strongly Coupled Field Theories

Strongly-coupled field theories describe both fundamental and applied quantum problems.

août 10, 2017

## Development of Terahertz Polariton Lasers

Theoretical and experimental results show that the polariton lasing mechanism is a promising basis for a compact, efficient source of terahertz radiation.

juillet 1, 2017

## Carbon Nanotube Monolayer Jospehson Junction Superconducting Qubit

Carbon nanotubes (CNTs) are a promising material for use in Josephson-Junctions (JJs) given their unique properties, such as high electrical conductivity, pristine surface, inherent nanoscale dimension, and silicon-compatible processing

juin 1, 2017

## Next Generation Quantum Sensors

We are developing new semiconductor p-n junctions and designing novel nanowire arrays that have the potential to significantly enhance the ability to detect light at the single photon level over an unprecedented wavelength range from the ultraviolet to infrared.

juin 1, 2017

## Two-Dimensional Quantum Materials and Heterostructures

Two-dimensional (2D) layers just one atom thick can be stripped from certain materials, such as graphene.

juin 1, 2017

## Quantum Information Processing with Molecular Lattices

The aim of the work is to develop theoretical tools to simulate and predict the behaviour of a one-dimensional chain of trapped dipolar molecules and to study the nature of entanglement as a design resource.

juin 1, 2017

## Qubits and Quantum Effects in Biology

It is unknown whether biological processes make direct use of quantum effects, as opposed to depending merely on the influence of quantum physics on chemical bonding and molecular structure.

juin 1, 2017

## Fabrication of Ultra Low Noise RF SQUID Amplifiers

A superconducting quantum interference device (SQUID) is an extremely sensitive magnetic field detector.

juin 1, 2017

## Distributing Multimode Entanglement with Microwave Photons

Microwaves have enabled numerous classical technologies, in part because they propagate through air with little energy loss.

mars 6, 2017

## Topological Quantum Computing on Majorana Platform

Full-scale quantum computing will require the capability for error-tolerant quantum information processing.

janvier 11, 2017

## Quantum Sensing with Small Quantum Systems

Summary There are small quantum systems over which we have very good control and which have long lifetimes. Examples include the phosphorous (P) defect in silicon (Si) and the nitrogen vacancy (NV) defect in diamond. With P defect in Si, we focus on improving our understanding of the hyperpolarization mechanism to better enable engineering of […]

décembre 1, 2016

## Extensible Technology for a Medium-Scale Superconducting Quantum Processor

Summary Superconducting quantum bits, or qubits, use circuits made from superconducting materials to harness quantum mechanical states. These devices contain many atoms, but can behave as simple, controllable qubits. We are building technologies for the control and measurement of superconducting qubits to enable the first demonstration of an extensible, medium-scale quantum processor. Our approach […]

novembre 28, 2016

## Molecular Scale Magnetic Resonance Imaging

Through its phenomenal ability to image soft tissues, magnetic resonance imaging (MRI) has revolutionized both clinical medicine and research biomedicine.

septembre 9, 2016

## Entangled States of Beams and their Applications

Summary With David Cory and collaborators at the National Institute of Standards and Technology we explore how to engineer beams of neutron or photons that carry entanglement. The degrees of freedom that can be entangled include spin (polarization), momentum, displacement, and angular momentum. These have potential applications ranging from studies of helical internal magnetic fields […]

septembre 7, 2016

## Quantum Dynamics of Cavity Interactions with Spin Ensembles

Summary High quality factor cavities can be powerful control elements for ensembles of spins, enabling unitary control as well as on demand cooling. They can also be used to couple two otherwise non-interacting ensembles. The goal of the project is to explore the physics and engineering of such systems both theoretically and experimentally. The laboratory contains a […]

septembre 7, 2016