Tootfinder

Steady-state entanglement of spin qubits mediated by non-reciprocal and chiral magnons
Martijn Dols, Mikhail Cherkasskii, Victor A. S. V. Bittencourt, Carlos Gonzalez-Ballestero, Durga B. R. Dasari, Silvia Viola Kusminskiy
https://arxiv.org/abs/2509.13094

Steady-state entanglement of spin qubits mediated by non-reciprocal and chiral magnons
We propose a hybrid quantum system in which a magnet supporting non-reciprocal magnons, chiral magnons, or both mediates the dissipative and unidirectional coupling of spin qubits. By driving the qubits, the steady state of this qubit-qubit coupling scheme becomes the maximally entangled Bell state. We devise a protocol where the system converges to this entangled state and benchmark it including qubit decay and dephasing. The protocol is numerically tested on a hybrid system consisting of nitr…

Path-Oblivious Entanglement Swapping for the Quantum Internet
Vincent Mutolo, Rhea Parekh, Dan Rubenstein
https://arxiv.org/abs/2509.13993 https://arxiv.or…

Path-Oblivious Entanglement Swapping for the Quantum Internet
Proposed Bell pair swapping protocols, an essential component of the Quantum Internet, are planned-path: specific, structured, routing paths are reserved prior to the execution of the swapping process. This makes sense when one assumes the state used in the swapping process is expensive, fragile, and unstable. However, lessons from classical networking have shown that while reservations seem promising in concept, flexible, reservation-light or free approaches often outperform their more restric…

Loss-tolerant parallelized Bell-state generation with a hybrid cat qudit
Z. M. McIntyre, W. A. Coish
https://arxiv.org/abs/2509.08577 https://arxiv.org/pdf…

Loss-tolerant parallelized Bell-state generation with a hybrid cat qudit
Having multiple Bell pairs shared by distant quantum registers provides a key resource for both quantum networks and distributed quantum computing. In this paper, we present a protocol for parallelized Bell-pair generation that uses the phase of a coherent light pulse to encode a qudit, enabling the simultaneous generation of multiple Bell pairs. By encoding a qudit in a basis of light-matter Schrödinger's cat states, the loss of a photon in transit can be detected through an $XX$ parity syndr…

from my link log —
Electricity transmission network unavailability: the cause of rising wind farm curtailment costs in Britain.
https://ukerc.ac.uk/news/transmission-network-unavailability-the-quiet-…

Transmission Network Unavailability – the Quiet Driving Force Behind Rising Curtailment Costs in Great Britain
In this blog, Callum MacIver and Keith Bell set out to dig a little deeper into the current state of wind curtailment.

Bell states for fermions in loop quantum gravity
Hanno Sahlmann, Martin Zei{\ss}
https://arxiv.org/abs/2508.04704 https://arxiv.org/pdf/2508.04704

Bell states for fermions in loop quantum gravity
Fermion fields are fundamental for the description of nature and also fit very naturally into the framework of loop quantum gravity. Motivated partially by proposals to use gravitationally mediated entanglement of matter as a witness for the quantum nature of gravity, we investigate how such entanglement can be defined and investigated in loop quantum gravity. In particular, we ask how a pair of fermions in a Bell state could be described in loop quantum, gravity. We demonstrate that the noti…

V*: An Efficient Motion Planning Algorithm for Autonomous Vehicles
Abdullah Zareh Andaryan, Michael G. H. Bell, Mohsen Ramezani, Glenn Geers
https://arxiv.org/abs/2508.06404 htt…

V*: An Efficient Motion Planning Algorithm for Autonomous Vehicles
Autonomous vehicle navigation in structured environments requires planners capable of generating time-optimal, collision-free trajectories that satisfy dynamic and kinematic constraints. We introduce V*, a graph-based motion planner that represents speed and direction as explicit state variables within a discretised space-time-velocity lattice. Unlike traditional methods that decouple spatial search from dynamic feasibility or rely on post-hoc smoothing, V* integrates both motion dimensions dir…

Geometry-Controlled Freezing and Revival of Bell Nonlocality through Environmental Memory
Mohamed Hatifi
https://arxiv.org/abs/2508.07046 https://arxiv.org…

Geometry-Controlled Freezing and Revival of Bell Nonlocality through Environmental Memory
We show that the distance between two qubits coupled to a structured reservoir acts as a single geometric control that can store, revive, or suppress Bell nonlocality. In a mirror-terminated guide, quantum correlations lost to the bath return at discrete recurrence times, turning a product state into a Bell-violating one without any entangling drive (only local basis rotations/readout). In the continuum limit, we derive closed-form criteria for the emergence of nonlocality from backflow, and in…

Optimality of universal conclusive entanglement purification protocols
Alexandre C. Orthey, Aby Philip, Tulja Varun Kondra, Alexander Streltsov
https://arxiv.org/abs/2509.09423 …

Optimality of universal conclusive entanglement purification protocols
Entanglement purification is essential for quantum technologies; yet, rigorous bounds on the success probability for universal protocols -- those requiring no prior knowledge about the input state -- have remained underexplored. We establish such fundamental limits for conclusive protocols distilling perfect Bell states from a pure two-qubit states by deriving the optimal success probability starting with: two copies of a state with known Schmidt basis, and four copies of a state with unknown S…

Improved Hamiltonian learning and sparsity testing through Bell sampling
Savar D. Sinha, Yu Tong
https://arxiv.org/abs/2509.07937 https://arxiv.org/pdf/250…

Improved Hamiltonian learning and sparsity testing through Bell sampling
We consider the problem of learning an $M$-sparse Hamiltonian and the related problem of Hamiltonian sparsity testing. Through a detailed analysis of Bell sampling, we reduce the total evolution time required by the state-of-the-art algorithm for $M$-sparse Hamiltonian learning to $\widetilde{\mathcal{O}}(M/ε)$, where $ε$ denotes the $\ell^{\infty}$ error, achieving an improvement by a factor of $M$ (ignoring the logarithmic factor) while only requiring access to forward time-evolution. We th…

Focused Ion Beam patterning of MnSb(1-101) based spintronic devcies
Stuart N. Holmes, Jonathan Gough, Ethan Dommett, Gavin R. Bell
https://arxiv.org/abs/2508.01838 https://

Focused Ion Beam patterning of MnSb(1-101) based spintronic devcies
Low temperature transport measurements are presented of ferromagnetic MnSb devices with the magnetic properties patterned using a Ga focused ion beam FIB system at 30 keV. FIB patterning introduces disorder and this is quantified in this paper through measurements of the longitudinal resistivity and the anomalous Hall effect contribution to the Hall conductivity. The MnSb structural phase is the niccolite phase with a surface state in addition to bulk states. FIB doses up to 1E16 Ga ions per sq…

Polarization-Controlled Dual-State Distribution of Bell and N00N Entanglement Over a Metro-Scale Commercial Quantum Network
Kazi Reaz, Md Mehdi Hassan, Jacob E. Humberd, Matthew L. Boone, Angel Fraire Estrada, Rick Mukherjee, H. R. Sadeghpour, Girish S. Agarwal, George Siopsis, Tian Li
https://arxiv.org/abs/2509.03701

Polarization-Controlled Dual-State Distribution of Bell and N00N Entanglement Over a Metro-Scale Commercial Quantum Network
We report the first demonstration of multiphoton, dual state entanglement distribution over a metropolitan scale commercial fiber network, implemented on the EPB Bohr IV quantum network in Chattanooga, TN, using an all fiber optic experimental platform. Employing a spatially degenerate, continuous wave type II SPDC biphoton source and fully fiber coupled linear optics, we generated a 4 photon entangled state. Through polarization projective measurements on two locally retained photons, we then …

Bell state measurements in quantum optics: a review of recent progress and open challenges
Luca Bianchi, Carlo Marconi, Davide Bacco
https://arxiv.org/abs/2509.18756 https://

Robots for Kiwifruit Harvesting and Pollination
Jamie Bell
https://arxiv.org/abs/2507.15484 https://arxiv.org/pdf/2507.15484

Robots for Kiwifruit Harvesting and Pollination
This research was a part of a project that developed mobile robots that performed targeted pollen spraying and automated harvesting in pergola structured kiwifruit orchards. Multiple kiwifruit detachment mechanisms were designed and field testing of one of the concepts showed that the mechanism could reliably pick kiwifruit. Furthermore, this kiwifruit detachment mechanism was able to reach over 80 percent of fruit in the cluttered kiwifruit canopy, whereas the previous state of the art mechani…

From Bell Products to GHZ: Quantum Memories via Emergent Hamiltonians
Anubhab Sur, Qiujiang Guo, Rubem Mondaini
https://arxiv.org/abs/2510.01117 https://ar…

From Bell Products to GHZ: Quantum Memories via Emergent Hamiltonians
With the advent of exquisite quantum emulators, storing highly entangled many-body states becomes essential. While entanglement typically builds over time when evolving a quantum system initialized in a product state, freezing that information at any given instant requires quenching to a Hamiltonian with the time-evolved state as an eigenstate, a concept we realize via an Emergent Hamiltonian framework. While the Emergent Hamiltonian is generically non-local and may lack a closed form, we show …

Piecemaker: a resource-efficient entanglement distribution protocol
Luise Prielinger, Kenneth Goodenough, Guus Avis, Stefan Krastanov, Don Towsley, Gayane Vardoyan
https://arxiv.org/abs/2508.14737

Piecemaker: a resource-efficient entanglement distribution protocol
We introduce multipartite entanglement distribution protocols that use a quantum switch to deliver stabilizer states to a number of remote end users. As in existing schemes, the first step in our protocols involves Bell pair generation between the switch and each end user. However, unlike existing schemes that wait for all Bell pairs to be established before distributing the desired state -- for example, via a projective measurement -- our approach stores only a minimal subset of Bell pairs whi…

Polynomial-time Extraction of Entanglement Resources
Si-Yi Chen, Angela Sara Cacciapuoti, Marcello Caleffi
https://arxiv.org/abs/2508.18024 https://arxiv.o…

Polynomial-time Extraction of Entanglement Resources
The extraction of EPR pairs and n-qubits GHZ states among remote nodes in quantum networks constitutes the resource primitives for end-to-end and on-demand communications. However, the Bell-VM problem, which determines whether a given graph state can be transformed into a set of Bell pairs on specific vertices (not necessarily remote), is known to be NP-complete. In this paper, we extend this problem, not only by focusing on nodes remote within generic graph states, but also by determining the …

Robust quantum communication through lossy microwave links
James D. Teoh, Nathanael Cottet, Patrick Winkel, Luke D. Burkhart, Luigi Frunzio, Robert J. Schoelkopf
https://arxiv.org/abs/2509.18547

Quantifying mixed-state entanglement via partial transpose and realignment moments
Poetri Sonya Tarabunga, Tobias Haug
https://arxiv.org/abs/2507.13840 htt…

Quantifying mixed-state entanglement via partial transpose and realignment moments
Entanglement plays a crucial role in quantum information science and many-body physics, yet quantifying it in mixed quantum many-body systems has remained a notoriously difficult problem. Here, we introduce families of quantitative entanglement witnesses, constructed from partial transpose and realignment moments, which provide rigorous bounds on entanglement monotones. Our witnesses can be efficiently measured using SWAP tests or variants of Bell measurements, thus making them directly impleme…

Demonstration of quantum error detection in a silicon quantum processor
Chunhui Zhang, Chunhui Li, Zhen Tian, Yan Jiang, Feng Xu, Shihang Zhang, Hao Wang, Yu-Ning Zhang, Xuesong Bai, Baolong Zhao, Yi-Fei Zhang, Huan Shu, Jiaze Liu, Kunrong Wu, Chao Huang, Keji Shi, Mingchao Duan, Tao Xin, Peihao Huang, Tianluo Pan, Song Liu, Guanyong Wang, Guangchong Hu, Yu He, Dapeng Yu

Demonstration of quantum error detection in a silicon quantum processor
Quantum error detection is essential in realizing large-scale universal quantum computation, especially for quantum error correction (QEC). However, key elements for FTQC have yet to be realized in silicon qubits. Here, we demonstrate quantum error detection on a donor-based silicon quantum processor comprising four-nuclear spin qubits and one electron spin as an auxiliary qubit. The entanglement capability of this system is validated through the establishment of two-qubit Bell state entangleme…

No-go theorem for quantum realization of extremal correlations
Sujan V. K, Ravi Kunjwal
https://arxiv.org/abs/2509.14879 https://arxiv.org/pdf/2509.14879…

No-go theorem for quantum realization of extremal correlations
The study of quantum correlations is central to quantum information and foundations. The paradigmatic case of Bell scenarios considers product measurements implemented on a multipartite state. The more general case of contextuality scenarios--where the measurements do not have to be of product form or even on a composite system--has been studied for the case of projective measurements. While it is known that in any Bell scenario extremal indeterministic correlations (e.g., Popescu-Rohrlich or P…

A Group-Theoretic Perspective on the PPT and Realignment Entanglement Criteria
Tobias C. Sutter, Christopher Popp, Beatrix C. Hiesmayr
https://arxiv.org/abs/2508.18393 https://

A Group-Theoretic Perspective on the PPT and Realignment Entanglement Criteria
Entanglement is a key feature in many quantum technologies, including secure communication protocols and quantum computing. However, detecting it in mixed quantum states remains a challenging task. While the PPT and realignment criteria are well-established tools for entanglement detection in general, and are especially effective in Bell-diagonal states, their connection to the underlying group structure of this state family has not been fully explored. In this work, we analyze the PPT and real…