Hi all,
Tomorrow Laura Boggia will tell us about her masterthesis she completed at IBM with Ivano Tavernelli, entitled 'Quantum Machine Learning for Anomaly Detection in High Energy Physics'. See below for the abstract. The talk will take place at 2pm in F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
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Abstract:
The advent of quantum computers gave rise to research for new applications that can be efficiently executed with the use of a quantum processor. Quantum …
[View More]Machine Learning (QML) is a prominent application for quantum devices and is described as the intersection between machine learning and quantum computation. High Energy Physics (HEP), as a computationally intensive domain of research, is a natural candidate for the application of QML. The search of new physics beyond the Standard Model (SM), that was initiated after the discovery of the Higgs particle, can potentially benefit from this new computing paradigm. We investigate the use of a QML protocol, namely Quantum Support Vector Machine (QSVM), for unravelling physics beyond the processes that can be described by the SM. The main differentiation of a QSVM relies on the use of a quantum feature map for the embedding of the input data via quantum circuits that can be efficiently evaluated on a quantum computer. In our work, we start from data sets containing simulated SM events and we randomly distort the data to introduce anomalies. Training on these two classes of data, we prepare a QML model that can classify anomalies on a complete data set coming from an Large Hadron Collider (LHC) experiment (SM and anomalies included). We perform a parametric analysis and identify how different parameters of the QSVM influence the performance of our workflow and determine an optimal parameter configuration for our use case. We demonstrate the potential of QSVM to better classify and identify patterns that will eventually lead to the understanding of new physics in HEP experiments. We confirm our findings with the use of a data set containing anomalous events caused by a graviton or Higgs particle and we also perform an experiment on an IBM quantum computer available in the cloud.
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Hi all,
Tomorrow our visitor Lev Vaidman will tell us about 'Experimental demonstrations of exotic quantum measurements'. See below for the abstract. The talk will take place at 2pm in HIT F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
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Abstract:
I will report first demonstrations of various types of quantum measurements. Nonlocal measurement - measurement of a property of a composite quantum system with spatially separated parts. Protective measurement - measuring …
[View More]expectation value of an observable with a single click. Robust weak measurement - measuring weak value of an observable with a single click. Modified interaction-free measurement: measurement that tells us that the place is empty without any particle passing through it.
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Hi all,
Tomorrow our visitor from NUS Josep Lumbreras will tell us about ''Multi-armed quantum bandits'’.
See below for the abstract. The talk will take place at 2pm in HIT F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
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Abstract:
We initiate the study of tradeoffs between exploration and exploitation in online learning of properties of quantum states. Given sequential oracle access to an unknown quantum state, in each round, we are tasked to choose an observable …
[View More]from a set of actions aiming to maximize its expectation value on the state (the reward). Information gained about the unknown state from previous rounds can be used to gradually improve the choice of action, thus reducing the gap between the reward and the maximal reward attainable with the given action set (the regret). We provide various information-theoretic lower bounds on the cumulative regret that an optimal learner must incur, and show that it scales at least as the square root of the number of rounds played. We also investigate the dependence of the cumulative regret on the number of available actions and the dimension of the underlying space. Moreover, we exhibit strategies that are optimal for bandits with a finite number of arms and general mixed states. If we have a promise that the state is pure and the action set is all rank-1 projectors the regret can be interpreted as the infidelity with the target state and we provide some support for the conjecture that measurement strategies with less regret exist for this case.
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Hi all,
Tomorrow our visitor from NUS Roberto Rubboli will tell us about ''Fundamental Limits on Correlated Catalytic State Transformations'’.
See below for the abstract. The talk will take place at 2pm in HIT F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
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Abstract:
Determining whether a given state can be transformed into a target state using free operations is one of the fundamental questions in the study of resources theories. Free operations in resource …
[View More]theories can be enhanced by allowing for a catalyst system that assists the transformation and is returned unchanged, but potentially correlated, with the target state. While this has been an active area of recent research, very little is known about the necessary properties of such catalysts. Here, we prove fundamental limits applicable to any correlated catalytic transformation by showing that a small residual correlation between catalyst and target state implies that the catalyst needs to be highly resourceful. In fact, the resources required diverge in the limit of vanishing residual correlation. We develop our results in a general resource theory framework and discuss its implications for the resource theory of athermality, the resource theory of coherence and entanglement theory.
https://arxiv.org/abs/2111.13356
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Hi all,
tomorrow Gian Gentinetta will tell us about his master thesis at IBM, entitled ''The complexity of quantum support vector machines''. See below for the abstract. The talk will take place at 2pm in F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
%%%%%
Abstract:
Quantum support vector machines employ quantum circuits to define the kernel function. It has been shown that this approach offers a provable exponential speedup compared to any known classical algorithm for …
[View More]certain data sets. The training of such models corresponds to solving a convex optimization problem either via its primal or dual formulation. Due to the probabilistic nature of quantum mechanics, the training algorithms are affected by statistical uncertainty, which has a major impact on their complexity. We show that the dual problem can be solved in O(M^4.67/ε^2) quantum circuit evaluations, where M denotes the size of the data set and ε the solution accuracy. We prove under an empirically motivated assumption that the kernelized primal problem can alternatively be solved in O(min{M^2/ε^6, 1/ε^10}) evaluations by employing a generalization of a known classical algorithm called Pegasos. Accompanying empirical results demonstrate these analytical complexities to be essentially tight. In addition, we investigate a variational approximation to quantum support vector machines and show that their heuristic training achieves considerably better scaling in our experiments.
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Hi all,
Tomorrow Martin Sandfuchs will tell us about his project with Ramona, entitled ''Computing key rates for device-independent quantum key distribution''. See below for the abstract. The talk will take place at 2pm in HIT F31.1 or on Zoom: https://ethz.zoom.us/j/362994444.
Best,
Ladina
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Abstract:
Quantum key distribution (QKD) aims to exploit the properties of quantum mechanics to produce a shared secret key between two distant users that is uncorrelated with the information held …
[View More]by an adversary. Device-independent QKD (DIQKD) tries to provide even stronger security guarantees by removing assumptions about how the devices operate. Unfortunately physical implementations of DIQKD pose significant experimental challenges and as a reaction a lot of theoretical work has gone into inventing improved protocols that can increase the tolerance to noise. A recent numerical method, developed by Peter Brown et al., has allowed for improved key rates in the asymptotic limit. In this presentation we demonstrate how this technique can be extended to the more realistic regime of finitely many key rounds. To do so we lower-bound the smooth min-entropy using the entropy accumulation theorem. We then build on previous DIQKD security proofs to propose a modified protocol which improves the threshold efficiency when performing DIQKD with lossy qubits.
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Hi all,
Tomorrow Xavier Coiteux-Roy of USI Lugano will tell us about
"Quantum-resistant cryptography for Bennett-Maxwell demons". See below for
the abstract. The meeting will take place in HIT F13 and on zoom at the
usual address https://ethz.zoom.us/j/362994444.
Best,
Joe
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Title: Quantum-resistant cryptography for Bennett-Maxwell demons
Abstract: I will present how the second law of thermodynamics allows in
principle to achieve information-theoretically secure cryptographic
…
[View More]primitives such as secret-key establishment and oblivious transfer. While
idealized, our proposed protocols explore the limits of logically and
thermodynamically reversible computation and act as a focal point to
contrast the properties of information in different physical theories.
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Hi all,
Tomorrow we'll hear from Alexander Schmidhuber, who did a semester project
with Esteban on "A covariant extension of the Page-Wootters mechanism to
spacetime". See the abstract below.
We can try a hybrid meeting for those who are at ETH and interested; I've
booked F31.1. The speaker will join us by zoom, so don't feel compelled to
join in person. The zoom link is the usual one,
https://ethz.zoom.us/j/362994444.
Best,
Joe
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Abstract:
Every observation in physics is made with …
[View More]respect to a frame of reference.
In any concrete scenario, this reference frame is constituted by a physical
system and thus subject to quantum phenomena such as entanglement and
superposition. A relativistic description of the laws of physics hence
needs to take into account such quantum reference frames. In this thesis,
we investigate a mechanism for temporal quantum reference frames developed
by Page and Wootters, and discuss its limitations. We show that two
a-priori different approaches to overcoming Kuchar's criticisms, developed
by Giovannetti, Lloyd & Maccone and Höhn, Smith & Lock, are equivalent.
Building upon this result, we construct a covariant extension of the
Page-Wootters mechanism to spacetime and derive the corresponding quantum
reference frame transformations for states and operators.
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