Articles by author: clee2

  • Physics Seminar – Dr. Lee Rozema on Photonic Quantum Computing: Finding Science Behind the Engineering

    Tuesday, July 09, 2024 | By

    Please join us on Wednesday July 24th, from 11:00am-12:00pm in GSB 306 for Dr. Lee Rozema’s seminar on Photonic Quantum Computing: Finding Science Behind the Engineering.

    Physics Department Seminar

    Lee Rozema
    University of Vienna

    Wednesday July 24th, 2024
    11:00am – 12:00pm, Room: GSB 306

    Photonic Quantum Computing: Finding Science behind the Engineering
    There is currently a race to build useful quantum devices, such as quantum computers or quantum communication systems, which promise to accomplish certain tasks in a way that classical systems cannot. For example, companies such as Google and IBM are pursuing quantum computers based on superconducting qubits, while Psi Quantum and Xanadu are attempting the same with photonic devices. In this presentation, I will review the physical requirements of quantum computing and discuss the pros and cons of the photonic approach. While some aspects of realizing a full-scale photonic quantum computer are well-understood and entering the realm of engineering, many interesting scientific questions remain. Some of these topics must be addressed to enable quantum computing, and others are of fundamental interest. To this end, I will present our recent work developing single-photon sources using ultra- thin nonlinear media [1,2], and, if time permits, present a recent line of research exploring alternative models of quantum computation based on superpositions of quantum processes [3,4]. Both of these research directions have potential applications, but they also highlight that the fields quantum information and quantum optics contain many open scientific questions.

  • Physics Seminar – Shengqiang Zhou on Pushing the Tellurium doping limit in Si by ion implantation for infrared optoelectronics

    Tuesday, July 09, 2024 | By

    Please join us on Thursday July 25th, from 11:00am-12:00pm in GSB 306 for Shengqiang Zhou’s seminar on Pushing the Tellurium doping limit in Si by ion implantation for infrared optoelectronics.

    Physics Department Seminar

    Shengqiang Zhou
    Helmholtz-Zentrum Dresden-Rossendorf

    Thursday July 25th, 2024
    11:00am – 12:00pm, Room: GSB 306

    Pushing the Tellurium doping limit in Si by ion implantation for infrared optoelectronics
    Tellurium is one of the deep-level impurities in Si, leading to states of 200-400 meV below the conduction band.   Non-equilibrium methods allow for doping deep-level impurities in Si well above the solubility limit, referred as hyperdoping, that can result in exotic properties, such as extrinsic photo-absorption well  below the Si bandgap [1]. The hyperdoping is realized by ion implantation and pulsed laser melting. We will present the resulting optical and electrical     properties as well as perspective applications for infrared photodetectors. With increasing the Te concentration, the samples undergo an insulator to metal transition [2]. The electron concentration obtained in Te-hyperdoped Si is approaching 1021 cm-3 and does not show saturation [3]. It is even higher than that of P or As doped Si, and mid-infrared localized surface plasmon resonances (LSPR) are also observed [4]. Using Te-doped Si, we demonstrate the room-temperature operation of infrared photodetectors with both vertical and planar device geometries (see Figure 1) [5,6]. The key parameters, such as the detectivity, the bandwidth and the rise/fall time, show competitiveness with commercial products. To understand the microscopic picture, we have performed Rutherford backscattering/channeling angular scans and hard x-ray spectroscopies [4, 7]. The Te-dimer complex sitting on adjacent Si lattice sites is the most preferred configuration at high doping concentration. Those substitutional Te-dimers are effective donors, leading to the insulator-to-metal transition, the non-saturating carrier concentration as well as the sub-band photoresponse. Our results are promising for the integration of active and passive photonic elements on a single Si chip, leveraging the advantages of planar CMOS technology.
    This work was financially supported by the German Research Foundation (WA4804/1-1, 445049905).

     

  • Assistant Professor Barak Shoshany’s Open-Source Work Looks to Accelerate Scientific Computing

    Wednesday, June 19, 2024 | By

    Assistant Professor of Physics Barak Shoshany, has created a free open-source package that enables researchers to improve the performance of their scientific software with a C++17 thread pool for high-performance scientific computing.

    Researcher’s open-source work looks to accelerate scientific computing

  • Brock University Physics Student Connor Wilson is the recipient of the 2024 Faculty of Math and Science Best MSc Thesis Award!

    Wednesday, June 19, 2024 | By

    A big congratulations to Brock Physics student Connor Wilson who is the recipient of the 2024 Faculty of Math and Science Best MSc Thesis Award in recognition of exceptional contributions in student research.

  • 2025 Proclaimed as the International Year of Quantum Science and Technology!

    Wednesday, June 12, 2024 | By

    Brock Physics and the Canadian Association of Physicists are excited that on June 7, the United Nations proclaimed 2025 as the International Year of Quantum Science and Technology (IYQ), increasing public awareness of the importance of quantum science and applications.
    The research at Brock Physics is centered on developing quantum materials for industry and infrastructure, clean energy and economic growth. Keep an eye out for public activities here at Brock during this year-long, worldwide initiative!

  • Physics Seminar – Jean-Sébastien Bernier

    Tuesday, May 21, 2024 | By

    Please join us on Monday May 27th, from 11:00am-12:00pm in GSB 306 for Jean-Sébastien Bernier’s seminar on Repulsively Bound Magnon Excitations of a Spin-1/2 XXZ Chain in a Staggered Transverse Field.

    Physics Department Seminar

    Jean-Sébastien Bernier
    University of Northern British Columbia

    Monday May 27th, 2024
    11:00am – 12:00pm, Room: GSB 306

    Repulsively Bound Magnon Excitations of a Spin-1/2 XXZ Chain in a Staggered Transverse Field
    Motivated by the chain antiferromagnet BaCo2V208, we study the excitation spectrum of the one-dimensional spin-1/2 XXZ chain with antiferromagnetic Ising anisotropy across a magnetic quantum phase transition induced by the application of a site-dependent transverse magnetic field. Considering a situation where the transverse magnetic field has a strong uniform component and a weaker staggered part, we determine the nature of the excitations giving rise to the spin dynamical structure factor using a combination of analytical approaches and the numerically exact time-dependent matrix product state method. Below the quantum phase transition, we identify high-energy many-body two-magnon and three-magnon repulsively bound states which are clearly visible due to the staggered component of the magnetic field. At high magnetic fields and low temperature, single magnons dominate the dynamics. These results are in very good agreement with terahertz spectroscopy measurements.

  • Joint Chemistry/Physics Seminar: Tigran Chalikian from U of T speaks on Conformational Propensities of Double-stranded G- and C-rich DNA Domains

    Friday, May 03, 2024 | By

    Prof. Tigran Chalikian, Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto

    Seminar title: Conformational Propensities of Double-stranded G- and C-rich DNA Domains
    Friday May 3rd, 12:00 – 1:00pm.
    Room: GSB 305

     

  • Save The Date – April 23 at 11am – R. Shankar’s Seminar on The Unfinished Theory of Topological Quantised Conductances

    Wednesday, April 17, 2024 | By

    Physics Department Seminar

    R. Shankar
    The Institute of Mathematical Science (retd.), Chennai, India

    Tuesday April 23, 2024
    11:00am, Room: GSB 408

    The Unfinished Theory of Topological Quantised conductances

    Abstract:
    After the discovery of the Quantum Hall Effect more than four decades ago, concepts of topology were successfully applied to understand it. Consequently, several other similar systems, Chern insulators, topological insulators were predicted and experimentally found. However, it is still not fully understood how the topology manifests as quantised conductances in open systems, namely samples coupled to metallic leads.

    In this talk we first review the relevant developments of the past decades. We then describe our attempts     to understand the system coupled to leads within the framework of a simple microscopic model

    Seminar_R__Shankar

  • Professor Thad Harroun Speaks on the Total Solar Eclipse and Brock’s Eclipse on the Escarpment Event

    Monday, April 15, 2024 | By

    Professor Thad Harroun appeared on YourTV Niagara, Hamilton Spectator, the St. Catharines Standard and Newstalk 610 CKTB to discuss the total solar eclipse and Brock’s Eclipse on the Escarpment event which was held on April 8th, 2024.

  • A Selection of Eclipse Images Captured at Brock

    Wednesday, April 10, 2024 | By

    Although the day of the eclipse was mostly overcast, the Physics Department was still able to capture some stunning images of the eclipse, as well as the eclipse event held on April 8, 2024.

    https://www.physics.brocku.ca/images/Eclipse2024/

     

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