Seminar

Unruh phenomena and thermalization for qudit detectors

Quantum-Nano Centre, 200 University Ave West, Room QNC 1201 Waterloo, ON CA N2L 3G1

The Unruh effect is the flat space analogue to Hawking radiation, describing how an observer in flat spacetime perceives the quantum vacuum state to be in a thermal state when moving along a constantly accelerated trajectory. This effect is often described operationally using the qubit-based Unruh-DeWitt detector.

We study Unruh phenomena for more general qudit detectors coupled to a quantized scalar field, noting the limitations to the utility of the detailed balance condition as an indicator for Unruh thermality of higher-dimensional qudit detector models. We illustrate these limitations using two types of qutrit detector models based on the spin-1 representations of SU(2) and the non-Hermitian generalization of the Pauli observables (the Heisenberg-Weyl operators).

[2309.04598] Unruh phenomena and thermalization for qudit detectors (arxiv.org)

Tight bounds for Pauli channel learning with and without entanglement

Quantum Nano Centre, 200 University Ave West, Room QNC 1201
Waterloo, ON CA N2L 3G1

Quantum entanglement is a crucial resource for learning properties from nature, but a precise characterization of its advantage can be challenging. In this work, we consider learning algorithms without entanglement as those that only utilize separable states, measurements, and operations between the main system of interest and an ancillary system. Interestingly, these algorithms are equivalent to those that apply quantum circuits on the main system interleaved with mid-circuit measurements and classical feedforward. Within this setting, we prove a tight lower bound for Pauli channel learning without entanglement that closes the gap between the best-known upper bound. In particular, we show that Θ(n^2/ε^2) rounds of measurements are required to estimate each eigenvalue of an n-qubit Pauli channel to ε error with high probability when learning without entanglement. In contrast, a learning algorithm with entanglement only needs Θ(1/ε^2) copies of the Pauli channel. Our results strengthen the foundation for an entanglement-enabled advantage for Pauli noise characterization. We will talk about ongoing experimental progress in this direction.

Reference: Mainly based on [arXiv: 2309.13461]

Quantum Nano Centre, 200 University Ave West, Room QNC 1201
Waterloo, ON CA N2L 3G1

Two randomly selected audience members will get the opportunity to present their work on the whiteboard for 20-minutes each.

IQC Seminar - Jong-Souk Yeo, Yonsei University

Quantum Nano Centre, 200 University Ave West, Room QNC 0101
Waterloo, ON, CA N2L 3G1

Biomimetic or nature-Inspired technologies are referring to the emerging fields where innovations are strongly inspired by the wisdom from nature or biological systems. Multiple levels of approaches are feasible from nature-inspiration – adaptation of how nature works, adoption of what nature provides, or replication of natural processes and functionalities for eco-friendly, sustainable, and highly efficient technologies. In this talk, nature-inspired approaches will be introduced for the nano-bio and nano-IT convergence research in the areas of nanostructure-cell interactions [1], nano-bio sensorics [2], biomimetic optical nanostructures [3], stretchable electronics [4], quantum plasmonics [5], and neuromorphic semiconductor technologies. Along with the research, recent efforts at Yonsei University will be introduced about the School of Integrated Technology where research and education are organically integrated for the technology convergence, and Yonsei Science Park where innovation ecosystem is established for IT-Bio Cluster Hub hosting Global Bio Campus and IBM quantum computer. This research was supported by the MSIT (Ministry of Science and ICT), Korea, under the ICT Consilience Creative program (IITP-2019-2017-0-01015) supervised by the IITP (Institute for Information & communications Technology Planning & Evaluation), the Ministry of trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT) through the International Cooperative R&D program (Project No. P0019630) and by the Human Frontier Science Program (RGP0047/2019).

Tracial embedded strategy: lifting MIP* tricks to MIPco

Quantum Nano Centre, 200 University Ave West, Room QNC 1201
Waterloo, ON CA N2L 3G1

Quantum non-local games have been an important object of study for the operator algebra and computer science community due to the recent ground-breaking result MIP*=RE. Although the majority of the study has been focused on the tensor product model in the non-local games literature recently, the commuting operator model is another model that is also considered in the non-local literature, and the difference between these two models forms the basis for disproving the famous Connes embeddings conjecture. In this talk, I will introduce a new set of strategies for the commuting operator model, the tracial embedded strategy, and sketch the proof that every strategy in the commuting operator model can be approximated by this set of strategies. Using this new characterization, I will present some similarities between the tensor product model and the commuting operator model in the complexity theory realm. This talk is based on the paper "Almost synchronous correlation in the commuting operator model".

Computational Entanglement Theory

Quantum Nano Centre, 200 University Ave W, Room QNC 1201
Waterloo, ON, CA N2L 3G1

Quantum entanglement is an important resource that contributes to the potential of quantum computers over classical computers. It turns out to be an interesting idea to quantify entanglement in states, and there are different approaches to this. We can, for example, consider the number of Bell states that are required to approximately produce a given state or the number of Bell states that can be produced from the state - these correspond to the 'entanglement cost’ and ‘distillable entanglement' respectively. Throughout this, we bear in mind a picture where Alice (A) and Bob (B) own a shared state, and are only able to perform LOCC operations on their respective systems. In practice, however, computational complexity must be taken into account. I will explain some recent developments towards taking computational complexity into account for these operational measures, as well as introducing pseudo-entanglement, and hopefully some quantum cryptography.

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IQC Seminar - Johannes Prell, Institute of Communication and Navigation, OSL German Aerospace Center (DLR) Oberpfaffenhofen, Germany

Quantum Nano Centre (QNC) Room 0101 200 University Ave West, Waterloo Ontario

Satellite based laser communication technology both classical and QKD (Q uantum K ey D istribution is gaining popularity and being increasingly commercial i zed . Optical ground stations serve as the receiv ing station in satellite to ground scenarios. The DLR institute of Communications and Navigation hosts an experimental optical ground station for research and demonstration purpose. Supporting increasingly demanding technical requirements from current and futu re missions and technology demonstrations, it was decided to replace the 40cm Cassegrain telescope an equip the new one with Nasmyth Ports for direct experiments, a Coudé Path to the lab and an Adaptive Optics System . This new 80cm (31.5inch) main apertur e diameter i nstrument is a Nasmyth Design Ritchey Chretien telescope The special feature is the C oudé P ath which is guiding the received light onto an optical table in a lab oratory room below the telescope mount (see figure 1 The usage of the Coudé Path is new implemented at DLR and offers a wide possibility for several different experiments with the same setup The optical propaga tion through a custom designed lens system inside the coudé path is optimized for wavelength s used for optical communication, like 589nm, 850nm, 1064nm and 1550nm. It is possible to use the setup as a receiving station and also as a transmitting facility f or beacon lasers . The transmitt ing system ca n be installed either beside the telescope as a side installation or even launched from the optical table through coudé path and telescope directly

The optical Experiment table in the lab is equipped with an Adaptive Optics ( System including fibe r coupling. This system uses a Shack Hartmann Wave front sensor, designed to match a deformable mirror in the “ f ried g eometry”. The system couples the light into a single mode fibe r , which can be con nected to a coherent or Quantum encrypted communications system. [ The telescope itself has four usable Nasmyth ports The first one is reserved for the coudé pa th, t wo others are equipped with optical benches directly on the telescope, and on the last one has a fixed classical laser communication receiving setup including two cameras one visible light and one infra red and a signal receiving united is installed References

[1] Andrew Paul Reeves, Ilija R. Hristovski, Alexandru Octavian Duliu, Stefanie H äu sler, Hela Friew Kelemu, Pia Lützen, Florian Moll, Eltimir Peev, Juraj Poliak, Amita Shrestha, Joana Sul Torres; Adaptive Optics Corrected Bi Directional Links with a Geo Stationary Satellite from the DLR KN Optical Ground Station Figure 1 OGSOP System Overvi ew

Impromptu Whiteboard Poster Session

Quantum Nano Centre (QNC) Room 1201, 200 University Avenue West, Waterloo, ON

This week’s student seminar will take place in the form of an impromptu whiteboard poster session, where attendees will be divided into groups and will discuss each other's current work using the whiteboard. This is to encourage students to talk about their work in progress, and practice communication skills by talking to non-experts (quantum is a big field!). As always, pizza will be provided for attendees after the seminar.

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Using Symmetries to Improve Quantum de Finetti Reductions

Quantum Nano Centre, 200 University Ave W, Room QNC 1201
Waterloo, ON, CA N2L 3G1

Kim de Laat, University of Waterloo

Quantum Nano Centre (QNC) Room 0101, 200 University Avenue West, Waterloo, ON

The field of quantum computing has a unique opportunity to pre-empt many of the inequities that have riddled AI and computer science. But radical technologies require new, radical solutions. In this talk, I take issue with the leaky pipeline metaphor as a way of structuring policy interventions concerning inequality in STEM fields. I outline three reasons why overreliance on the leaky pipeline metaphor is problematic: (1) it does not accurately represent the phenomenon it is meant to describe; (2) it is incomplete; and (3) it does not capture the full heterogeneity of experiences with inequality in STEM disciplines. I conclude the talk by sharing feedback from the quantum technology community concerning potential pitfalls in the pursuit of equity in quantum, and what we can do about it.