New HyperSpace collaboration, including Dr. Thomas Jennewein from the Institute for Quantum Computing, envisions secure quantum connections across the Atlantic Ocean.
Are you curious about the Quantum Encryption and Science Satellite mission, also known as QEYSSat? Are you wondering "Why put quantum in space"? Or perhaps you are curious to know what it takes to put quantum hardware in space? In this talk, we will discuss why it is advantageous to have quantum in space. We will also explore the various design challenges that need to be considered for space hardware. Finally, we will discuss the history of quantum space activities at the Institute for Quantum Computing, particularly QEYSSat, which is a joint project between the Canadian Space Agency (CSA) and the University of Waterloo.
Abstract: Multipolar quantum materials possess local moments carrying higher-rank quadrupolar or octupolar moments. These higher-rank multipolar moments arise due to strong spin-orbit coupling and local symmetry of the crystal-electric-field environment. In magnetic insulators, the interaction between multipolar local moments on frustrated lattices may promote novel quantum spin liquids. In heavy fermion systems, the interaction between multipolar local moments and conduction electrons may lead to unusual non-Fermi liquids and quantum criticality. In this talk, we first discuss a novel quantum spin ice state, a three-dimensional quantum spin liquid with emergent gauge field, that may have been realized in Ce2Zr2O7 and Ce2Sn2O7, where Ce3+ ions carry dipolar-octupolar moments. We present a theoretical analysis of possible quantum spin ice states in this system and compare the theoretical results of dynamical spin structure factors with recent neutron scattering experiments. Next, we present a theoretical model to describe the unusual Kondo effect and quantum criticality in Ce3Pd20Si6, where Ce3+ moments carry a plethora of dipolar, quadrupolar, and octupolar moments. We show that two consecutive Kondo-destruction-type phase transitions can occur with the corresponding Fermi surface reconstructions. We compare these results with existing experiments and suggest future ultrasound experiments for the detection of emergent quantum critical behaviors.
In this talk, we study the problem of designing worst-case to average-case reductions for quantum algorithms. For all linear problems, we provide an explicit and efficient transformation of quantum algorithms that are only correct on a small (even sub-constant) fraction of their inputs into ones that are correct on all inputs. This stands in contrast to the classical setting, where such results are only known for a small number of specific problems or restricted computational models. En route, we obtain a tight Ω(n^2) lower bound on the average-case quantum query complexity of the Matrix-Vector Multiplication problem...
Join us for Quantum Today, where we sit down with researchers from the University of Waterloo’s Institute for Quantum Computing (IQC) to talk about their work, its impact and where their research may lead.
Reliable entangled photon sources are important for testing fundamentals in quantum mechanics, achieving secure quantum key distribution, among other things. Quantum dots are a hot topic for precisely this need of the scientific community. Quantum dots act as artificial atoms by confining electrons and holes in wells. They emit polarization entangled photons in an exciton-biexciton cascade. The expected entangled state from the cascade is
The confining potential of these wells can be asymmetric which causes fine structure splitting in the intermediate energy level of the cascade.
The presented work offers a way to achieve perfectly entangled photon pairs with quantum dots in vertical nanowires, on demand and with a high count rate. Fine structure splitting is seen in all quantum dot systems whether they are quantum dots in nanowires, micropillars, or, self-assembled quantum dots. This proposal is universal because it can be used to compensate for energy dependent entanglement degradation in all entangled photon sources.
The fine structure splitting in the dot leads to a difference in energy of the photons in different polarizations. This renders the quantum dot system less effective for quantum key distribution applications. Therefore, countering fine structure splitting is highly desirable.
This talk will discuss the approach taken in Quantum Photonic Devices lab to counter the fine structure splitting.
Today, the Institute for Quantum Computing (IQC) is celebrating the roles of women in science. We strongly believe that by supporting and encouraging equity, diversity, and inclusivity in our community, IQC provides a welcoming environment for researchers from all backgrounds to study quantum information.
The Quantum Shorts festival celebrates independent short films inspired by quantum mechanics. Using ideas like the uncertainty principle and many-worlds interpretation, filmmakers from around the world have created five-minute wonders.
Free-space quantum channels for real world quantum information applications are rapidly emerging, with Canada developing the quantum encryption and science satellite (QEYSSat). For polarization-based systems, one challenge is aligning the reference frame of the polarization states. For example, the physical orientation of the satellites is crucial in maintaining the proper geometric reference frame alignment. However, reference frame independent (RFI) protocols overcome this issue because they don’t require all the polarization states to be fixed. Furthermore, using time bin encoding completely removes the need for a geometric reference, but presents its own challenges when used over a free space channel. In this talk, we will discuss the development done at the University of Waterloo towards the use of reference frame independent protocols for free-space quantum channels. Furthermore, we will discuss the benefits of using time bin encoding over free-space channels, and present our implementations of such systems and what they mean for future QEYSSat missions and applications on other platforms.
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A new study published today in Nature is changing our understanding of chemical reactions and overturning previous theoretical models by finding an unexpected resonance frequency during the reaction of two molecules.