Jonte HanceUniversity of Bristol | UB · Department of Electrical and Electronic Engineering
Jonte Hance
PhD Student (Quantum Communications and Foundations)
A final-year PhD student working to investigate, test and leverage foundational concepts in quantum mechanics/optics.
About
41
Publications
1,895
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98
Citations
Introduction
My research involves investigating foundational areas in quantum physics (such as interaction-free measurement, weak values, and statistical independence violation), with a view to evaluating and leveraging the effects these novel phenomena/areas have for the development of quantum technologies. This falls within EPSRC research themes in Quantum Technologies and Physics research area Quantum Optics and Information.
Additional affiliations
August 2018 - October 2020
DotQuantum
Position
- Consultant
Description
- Developed a new and innovative Quantum Key Distribution (QKD) protocol, to protect communications using the power of quantum physics. While there, was co-inventor of patent gb 1821135.9 (patent pending).
Education
October 2014 - July 2019
Publications
Publications (41)
In quantum mechanics, the wave function predicts probabilities of possible measurement outcomes, but not which individual outcome is realized in each run of an experiment. This suggests that it describes an ensemble of states with different values of a hidden variable. Here, we analyse this idea with reference to currently known theorems and experi...
We summarise different aspects of the measurement problem in quantum mechanics. We argue that it is a real problem which requires a solution, and identify the properties a theory needs to solve the problem. We show that no current interpretation of quantum mechanics solves the problem, and that, being interpretations rather than extensions of quant...
In a recent paper (Phys. Rev. A 105, 042220 (2022)), Daley et al claim that superdeterministic models are disfavoured against standard quantum mechanics, because such models overfit the statistics of a Bell-type experiment which the authors conducted. We argue here that their claim is based on a misunderstanding of what superdeterministic models ar...
We extend counterfactual, or exchange-free, imaging to the polarimetry of a polarising object. This allows imaging of these samples with far less absorbed energy-a key concern when imaging with high-frequency radiation. © 2022 The Author(s)
We extend exchange-free imaging to polarimetry of a polarising object. This allows imaging of these samples with far less absorbed energy-a key concern when imaging with high-frequency radiation. © 2022 The Author(s)
We explore how one might detect the dynamical quantum Cheshire cat proposed by Aharonov et al. We show that, in practice, we need to bias the initial state by adding/subtracting a small probability amplitude (`field') of the orthogonal state, which travels with the disembodied property, to make the effect detectable (i.e. if our initial state is $|...
It was recently argued by Catani et al that it is possible to reproduce the phenomenology of the double-slit experiment with a deterministic, local, and classical model (arXiv:2111.13727). The stated aim of their argument is to falsify the claim made by Feynman (in his third book of Lectures on Physics) that the double-slit experiment is "impossibl...
We extend counterfactual imaging to polarimetry of a polarising object. This allows imaging of these samples with far less absorbed energy-a key concern when imaging with high-frequency radiation. © 2022 The Author(s)
In a recent criticism (arXiv:2111.13357) of our paper arXiv:2111.09347, Drezet argues that we have forgotten to consider superpositions of detector eigenstates. However, such superpositions do not occur in the models our paper is concerned with. We also note that no one has ever observed such detector superpositions.
The Delayed-Choice Quantum Eraser experiment is commonly interpreted as implying that in quantum mechanics a choice made at one time can influence an earlier event. We here suggest an extension of the experiment that results in a paradox when interpreted using a local realist interpretation combined with backward causation ("retrocausality"). We ar...
Data (and code used to analyse the data) used in the weak measurement experiment in the paper "Do the Laws of Physics Prohibit Counterfactual Communication" (arXiv:1806.01257).
We have developed a protocol for ghost imaging that is always counterfactual - while imaging an object, no light interacts with it. This provides both better visibility/SNR and less absorbed intensity than ghost imaging.
© 2021 The Author(s)
We investigate the weak trace method for determining the path of a quantum particle. Specifically, looking at nested interferometer experiments, when internal interferometers are tuned to destructive interference, we show that the weak trace method gives misleading results. Obtaining the weak value of the position operator necessarily perturbs the...
In quantum mechanics, the wave-function only predicts probabilities of measurement outcomes, not individual outcomes. This suggests that it describes an ensemble of states with different values of a hidden variable. Here, we analyse this idea with reference to currently known theorems and experiments. We argue that the $\psi$-ontic/epistemic distin...
In a recent paper (arXiv:2107.04761), Sen critiques a superdeterministic model of quantum physics, Invariant Set Theory, proposed by one of the authors. He concludes that superdeterminism is `unlikely to solve the puzzle posed by the Bell correlations'. He also claims that the model is neither local nor ψ-epistemic. We here detail multiple inaccura...
Bell's theorem is often said to imply that quantum mechanics violates local causality, and that local causality cannot be restored with a hidden-variables theory. This however is only correct if the hidden-variables theory fulfils an assumption called Statistical Independence. Violations of Statistical Independence are commonly interpreted as corre...
We have developed a protocol for ghost imaging that is always exchange-free-while imaging an object, no light interacts with it. This provides both better visibility/SNR and less absorbed intensity than ghost imaging. © 2021 The Author(s)
We have developed a protocol for ghost imaging that is always counterfactual - while imaging an object, no light interacts with it. This provides both better visibility/SNR and less absorbed intensity than ghost imaging. © 2021 The Author(s)
In a recent paper (Scheme of the arrangement for attack on the protocol BB84, Optik 127(18):7083-7087, Sept 2016), a protocol was proposed for using weak measurement to attack BB84. This claimed the four basis states typically used could be perfectly discriminated, and so an interceptor could obtain all information carried. We show this attack fail...
Wolfram Mathematica code used to generate the simulations of the exchange-free controlled-Z gate, exchange-free teleportation, and exchange-free telecloning, which we use to give fidelity and efficiency rates in the paper "Deterministic Teleportation and Universal Computation Without Particle Exchange".
In a recent paper (Scheme of the arrangement for attack on the protocol BB84, Optik 127(18):7083-7087, Sept 2016), a protocol was proposed for using weak measurement to attack BB84. This claimed the four basis states typically used could be perfectly discriminated, and so an interceptor could obtain all information carried. We show this attack fail...
We have developed a protocol for ghost imaging that is always counterfactual-while imaging an object, no light interacts with it. This provides both better visibility/SNR and less absorbed intensity than ghost imaging. © 2020 The Author(s)
A correction to this paper has been published: https://doi.org/10.1007/s10701-021-00450-z
We model backscatter for electric fields propagating through optical micro-ring resonators, as occurring both in-ring and in-coupler. These provide useful tools for modelling transmission and in-ring fields in these optical devices. We then discuss spontaneous four-wave mixing and use the models to obtain heralding efficiencies and rates. We observ...
We identify points of difference between Invariant Set Theory and standard quantum theory, and evaluate if these would lead to noticeable differences in predictions between the two theories. From this evaluation, we design a number of experiments, which, if undertaken, would allow us to investigate whether standard quantum theory or invariant set t...
In discussion of the interpretation of quantum mechanics the terms 'ontic' and 'epistemic' are often used in the sense of pertaining to what exists, and pertaining to cognition or knowledge respectively. The terms are also often associated with the formal definitions given by Harrigan and Spekkens for the wavefunction in quantum mechanics to be ψ-o...
We give a protocol for ghost imaging in a way that is always counterfactual - while imaging an object, no light interacts with that object. This extends the idea of counterfactuality beyond communication, showing how this interesting phenomenon can be leveraged for metrology. Given, in the infinite limit, no photons ever go to the imaged object, it...
Teleportation is a cornerstone of quantum technologies, and has played a key role in the development of quantum information theory. Pushing the limits of teleportation is therefore of particular importance. Here, we apply a different aspect of quantum weirdness to teleportation---namely exchange-free computation at a distance. The controlled-phase...
The generalisation of counterfactual communication - where classical information is sent without exchanging particles (exchange-free) - to sending quantum information, poses significant experimental challenges. Here, we show how to directly communicate an arbitrary qubit, not only exchange-free but also without the sender having to implement a quan...
We model backscatter for electric fields propagating through optical micro-ring resonators, as occurring both in-ring and in-coupler. These provide useful tools for modelling transmission and in-ring fields in these optical devices. We then discuss spontaneous four-wave mixing and use the models to obtain heralding efficiencies and rates. We observ...
Quantum Counterfactual Communication is the recently-proposed idea of using quantum physics to send messages between two parties, without any matter/energy transfer associated with the bits sent. While this has excited massive interest, both for potential 'unhackable' communication, and insight into the foundations of quantum mechanics, it has been...
Counterfactual definiteness is shown from analysis of Bell's Theorem to be the factor separating classical from quantum theories. From this, it is shown that, by replacing it with 'counterfactual semi-definiteness', the definiteness of possible options available after a measurement event, some apt analysis of possible states can be kept. While not...
We formalize Salih et al’s Counterfactual Communication Protocol (arXiv2018), which allows it not only to be used in with other modes than polarization, but also for interesting extensions (e.g. sending superpositions from Bob to Alice).
We formalize Salih et al's Counterfactual Communication Protocol (arXiv2018), which allows it not only to be used in with other modes than polarization, but also for interesting extensions (e.g. sending superpositions from Bob to Alice).
It has been conjectured that counterfactual communication is impossible, even for post-selected quantum particles. We challenge this by proposing exactly such a counterfactual scheme where---unambigiuously---none of Alice's photons has been to Bob. We demonstrate counterfactuality using a consistent histories approach as well as a weak measurement...
Projects
Projects (3)
We aim to investigate superdeterministic extensions to quantum physics (such as Invariant Set Theory), to see if they provide us a way of violating Bell Inequalities without requiring Bell-nonlocality. We examine to what extent we need to violate statistical independence in these theories, to see if superdeterminism really is the "death of science", as often claimed.
In this project, we aim to explore the foundational underpinnings of weak values, with specific reference to whether we can take the limit of weakness of weak interactions to zero, or whether this limit is singular (i.e. whether any interaction, regardless how weak, is fundamentally different to no interaction).
Quantum Counterfactual Communication is the recently-proposed idea of using quantum mechanics to send messages between two parties without any matter/energy travelling between them. While this novel idea has excited massive interest, both for potential ‘un-hackable’ communications, and insight into the foundations of quantum mechanics, it has also raised a number of problems, from the practical (physical implementation, effects of loss), to the foundational (what carries the information, relation to quantum thermodynamics, implications for wavefunction reality). Further, it poses a ripe area for further development (such as towards counterfactual quantum teleportation, state preparation, or higher-dimensional counterfactuality).
