# phys: probing quantum mechanics with nanoparticle matter-wave interferometry.

<< ️The quantum superposition principle is a fundamental concept of physics and the basis of numerous quantum technologies. Yet, it is still often regarded counterintuitive because we do not observe its key features on the macroscopic scales of our daily lives. It is, therefore, interesting to ask how quantum properties persist or change as we increase the size and complexity of objects. >>

<< ️A model test for this question can be realized by matter-wave interferometry, in which the motion of individual massive particles becomes delocalized and needs to be described by a wave function that spans regions far larger than the particle itself. Over the years, this has been explored with a series of objects of increasing mass and complexity and a growing community aims at pushing this to ever larger limits. >>

<< ️Here (AA) present an experimental platform that extends matter-wave interference to large metal clusters, a qualitatively new material class for quantum experiments. (They) specifically demonstrate quantum interference of sodium nanoparticles, which can each contain more than 7,000 atoms at masses greater than 170,000 Da. They propagate in a Schrödinger cat state with a macroscopicity of μ = 15.5, surpassing previous experiments by an order of magnitude. >>

Sebastian Pedalino, Bruno E. Ramírez-Galindo, Richard Ferstl, et al. Probing quantum mechanics with nanoparticle matter-wave interferometry. Nature 649, 866–870. Jan 21, 2026.

https://www.nature.com/articles/s41586-025-09917-9

Also: keyword 'quantum' in FonT

https://flashontrack.blogspot.com/search?q=quantum

Keywords: particles, quantum mechanics, quantum superposition.

# gst: quantum avalanche stability of many-body localization with power-law interactions.

<< ️(AA) investigate the stability of the many-body localized (MBL) phase against quantum avalanche instabilities in a one-dimensional Heisenberg spin chain with long-range power-law interactions (V ∝ r−α). >>

<< ️(They) finite-size scaling analysis of entanglement entropy identifies a critical interaction exponent αc ≈ 2, which separates a fragile regime, characterized by an exponentially diverging critical disorder, from a robust short-range regime. >>

<< ️(AA) results confirm that the MBL phase remains asymptotically stable in the thermodynamic limit when disorder exceeds an interaction-dependent threshold. >>

Longhui Shen, Bin Guo, Zhaoyu Sun. Quantum Avalanche Stability of Many-Body Localization with Power-Law Interactions. arXiv: 2601.13485v1 [cond-mat.dis-nn]. Jan 20, 2026.

https://arxiv.org/abs/2601.13485

Also: disorder, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, avalanche, avalanche stability, entanglement entropy, criticality. 

# gst: dynamical entanglement percolation with spatially correlated disorder.

<< ️The distribution of entanglement between the nodes of a quantum network plays a fundamental role in quantum information applications. In this work, (AA) investigate the dynamics of a network of qubits where each edge corresponds to an independent two-qubit interaction. By applying tools from percolation theory, (They) study how entanglement dynamically spreads across the network. (They) show that the interplay between unitary evolution and spatially correlated disorder leads to a non-standard percolation phenomenology, significantly richer than uniform bond percolation and featuring hysteresis. >>

Lorenzo Cirigliano, Valentina Brosco, Claudio Castellano, et al. Dynamical entanglement percolation with spatially correlated disorder. arXiv: 2601.05925v1 [quant-ph]. Jan 9, 2026.

https://arxiv.org/abs/2601.05925

Also: network, disorder, in https://www.inkgmr.net/kwrds.html     qubit, in https://flashontrack.blogspot.com/search?q=qubit

Keywords: gst, networks, classical complex networks, quantum networks, qubit, disorder, percolation, entanglement, hysteresis.

#qubit: more in quantum weirdness, the superposition of unitaries (a particle simultaneously follows two distinct sets of movement instructions)

<< ️Arijit Chatterjee at the Indian Institute of Science Education and Research and his colleagues theorized that a new kind of quantum motion, in which a particle follows two distinct sets of movement instructions simultaneously, (..). They called this superposition of unitaries. >>

Paul Arnold. Experimental proof shows quantum world is even stranger than previously thought. Phys.org. Nov 25, 2025.

https://phys.org/news/2025-11-experimental-proof-quantum-world-stranger.html

Arijit Chatterjee, H.S. Karthik, T.S. Mahesh, A.R. Usha Devi. Enhanced non-macrorealism: Extreme violations of Leggett-Garg inequalities for a system evolving under superposition of 

unitaries. arXiv: 2411.02301v1 [quant-ph]. Nov 4, 2024. https://arxiv.org/abs/2411.02301.  Phys. Rev. Lett. 135, 220202. Nov 24, 2025. https://journals.aps.org/prl/abstract/10.1103/vydp-9qqq

Keywords: qubit, quantum systems & decoherence, quantum-to-classical transition.

# gst: apropos of Parrondo paradox, controlling quantum chaos via Parrondo strategies on noisy intermediate-scale quantum hardware

<< ️Advancements in noisy intermediate-scale quantum (NISQ) computing are steadily pushing these systems toward outperforming classical supercomputers on specific well-defined computational tasks. In this work (AA) explore and control quantum chaos in NISQ systems using discrete-time quantum walks (DTQWs) on cyclic graphs. To efficiently implement quantum walks on NISQ hardware, (They) employ the quantum Fourier transform to diagonalize the conditional shift operator, optimizing circuit depth and fidelity. >>

<< ️(AA) experimentally realize the transition from quantum chaos to order via DTQW dynamics on both odd and even cyclic graphs, specifically 3- and 4-cycle graphs, using the counterintuitive Parrondo paradox strategy across three different NISQ devices. >>

<< ️While the 4-cycle graphs exhibit high-fidelity quantum evolution, the 3-cycle implementation shows significant fidelity improvement when augmented with dynamical decoupling pulses. (Their) results demonstrate a practical approach to probing and harnessing controlled chaotic dynamics on real quantum hardware, laying the groundwork for future quantum algorithms and cryptographic protocols based on quantum walks. >>

Aditi Rath, Dinesh Kumar Panda, Colin Benjamin. Controlling quantum chaos via Parrondo strategies on noisy intermediate-scale quantum hardware. Phys. Rev. E 112, 054219. Nov 18, 2025.

https://journals.aps.org/pre/abstract/10.1103/m89r-2dy5

arXiv: 2506.11225v2 [quant-ph]. Nov 4, 2025.

https://arxiv.org/abs/2506.11225

Also: parrondo, noise, walk, walking, order, chaos, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, parrondo, noise, walk, walking, quantum walk, order, chaos, quantum chaos, transition, dynamical decoupling pulses, cryptography.

# astro: could we observe an exploding black hole in the near future?

<< ️Observation of gamma rays from an exploding black hole would provide strong evidence for primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect constraints suggest that direct observation of an exploding Schwarzschild black hole at current or upcoming gamma ray observatories is implausible. >>

<< ️(AA) introduce a dark-QED (Quantum Electrodynamics) toy model consisting of a dark photon and a heavy dark electron. In this scenario a population of light primordial black holes charged under the dark 𝑢⁡(1) symmetry can become quasiextremal, so they survive much longer than if they were uncharged, before discharging and exhibiting a Schwarzschild-like final explosion. (They) show that the answer is “yes,” in this scenario the probability of observing an exploding black hole over the next 10 years could potentially be over 90%. >>

Michael J. Baker, Joaquim Iguaz Juan, et al. Could We Observe an Exploding Black Hole in the Near Future? Phys. Rev. Lett. 135, 111002. Sep 10, 2025. 

https://journals.aps.org/prl/abstract/10.1103/nwgd-g3zl

Marric Stephens. Dark Charge Could Make Exploding Black Holes More Common. (Synopsis). Physics 18, s112. Sep 10, 2025. 

https://link.aps.org/doi/10.1103/Physics.18.s112

Also: black hole, astrophysics, in https://www.inkgmr.net/kwrds.html 

Keywords: black holes, evaporating black holes, astrophysics.

# gst: a journey into billiard systems

<< ️Have you ever played or watched a game of pool? If so, you have already seen a billiard system in action. In mathematics and physics, a billiard system describes a ball that moves in straight lines and bounces off walls. Despite these simple rules, billiard systems can produce remarkably rich behaviors: some table shapes generate regular, periodic patterns, while others give rise to complete chaos. >>

<< Scientists also study what happens when (They) shrink the ball down to the size of an electron to a world where quantum effects take over and the familiar reflection rules no longer apply. >>

<< ️In this article, (AA) discuss billiard systems in their many forms and show how such a simple setup can reveal fundamental insights into the behavior of nature at both classical and quantum scales. >>

Weiqi Chu, Matthew Dobson. What Do Bouncing Balls Tell Us About the Universe? A Journey into Billiard Systems. arXiv: 2508.18519v1 [math.DS]. Aug 25, 2025.

https://arxiv.org/abs/2508.18519

Also: billiard, transition, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, billiard, transition, chaos.

# gst: hidden qu-classical correspondence in chaotic billiards revealed by mutual information.

<< ️Avoided level crossings, commonly associated with quantum chaos, are typically interpreted as signatures of eigenstate hybridization and spatial delocalization, often viewed as ergodic spreading. >>

<< ️(AA) show that, contrary to this expectation, increasing chaos in quantum billiards enhances mutual information between conjugate phase space variables, revealing nontrivial correlations. Using an information-theoretic decomposition of eigenstate entropy, (They) demonstrate that spatial delocalization may coincide with increased mutual information between position and momentum. >>

<< These correlations track classical invariant structures in phase space and persist beyond the semiclassical regime, suggesting a robust information-theoretic manifestation of quantum-classical correspondence. >>

Kyu-Won Park, Soojoon Lee, Kabgyun Jeong. Hidden quantum-classical correspondence in chaotic billiards revealed by mutual information. Phys. Rev. E 112, 024209. Aug 13, 2025.

https://journals.aps.org/pre/abstract/10.1103/qpxx-csdj

arXiv:2505.08205v1 [nlin.CD]. May 13, 2025.

https://arxiv.org/abs/2505.08205

Also: billiard, chaos, waves, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, billiard, chaos, qu-chaos, waves, quantum-to-classical transition

# gst: topologically nontrivial multicritical points.

<< ️Recently, the intriguing interplay between topology and quantum criticality has been unveiled in one-dimensional topological chains with extended nearest-neighbor couplings. In these systems, topologically distinct critical phases emerge with localized edge modes despite the vanishing bulk gap. >>

<< ️In this work, (AA) study the topological multicritical points at which distinct gapped and critical phases intersect. Specifically, (They) consider a topological chain with coupling up to the third nearest neighbors, which shows stable localized edge modes at the multicritical points. These points possess only nontrivial gapped and critical phases around them and are also characterized by the quadratic dispersion around the gap-closing points. >>

<< Further, (AA) analyze the nature of zeros in the vicinity of the multicritical points by calculating the discriminants of the associated polynomial. The discriminant uniquely identifies the topological multicritical points and distinguishes them from the trivial ones.  >>

AA << finally study the robustness of the zero-energy modes at the multicritical points at weak disorder strengths, and reveal the presence of a topologically nontrivial gapless Anderson-localized phase at strong disorder strengths. >>

Ranjith R Kumar, Pasquale Marra. Topologically nontrivial multicritical points. arXiv: 2507.11120v1 [cond-mat.dis-nn]. Jul 15, 2025.

https://arxiv.org/abs/2507.11120

Also: disorder & fluctuations, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, disorder & fluctuations, criticality, multicritical points, transition.

# gst: the turbulence development at its initial stage, a scenario based on the idea of vortices decay.

<< ️In this paper, a model of the development of a quantum turbulence in its initial stage is proposed. The origin of the turbulence in the suggested model is the decay of vortex loops with an internal structure. >>

AA << ️consider the initial stage of this process, before an equilibrium state is established. As result of (Their) study, the density matrix of developing turbulent flow is calculated. The quantization scheme of the classical vortex rings system is based on the approach proposed by the author earlier. >>

S.V. Talalov. The turbulence development at its initial stage: a scenario based on the idea of vortices decay. arXiv: 2303.05908v3 [physics.flu-dyn]. Feb 16, 2024.

https://arxiv.org/abs/2303.05908

Also: << Lo "smoothing" e', nell' essenziale, un atteggiamento, un comportamento piu' o meno automatico, una tecnica, una prassi. (..) tutte le volte che uno "smoother" livella un vortice (piu' verosimilmente crede di aver circoscritto un vortice per livellarlo), se non e' accorto (non lo e' quasi mai) mentre cerca di spianare lo potenzia e, allo stesso tempo - questo e' il fatto curioso - puo' avere inconsapevolmente generato i presupposti per accenderne in prospettiva almeno un' altro. Oppure altri due. Oppure 'n'. >> In: Smoothers. Notes (quasi-stochastic poetry). Mar 27, 2006.

http://inkpi.blogspot.com/2006/03/1980-smoothers.html

Also: turbulence, vortex, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, turbulence, vortex.

# gst: energy spectra and fluxes of 2D turbulent quantum droplets.

AA << explore the energy spectra and associated fluxes of turbulent two-dimensional quantum droplets subjected to a rotating paddling potential which is removed after a few oscillation periods. A systematic analysis on the impact of the characteristics (height and velocity) of the rotating potential and the droplet atom number reveals the emergence of different dynamical response regimes. >>

<< ️Significant distortions are observed in the droplet periphery in the presence of a harmonic trap. A direct energy cascade (from large to small length scales) is mainly identified through the flux. >>

Their << ️findings offer insights into the turbulent response of exotic phases of matter, featuring quantum fluctuations, and may inspire investigations aiming to unravel self-similar nonequilibrium dynamics. >>

Shawan Kumar Jha, Mahendra K. Verma, et al. Energy spectra and fluxes of two-dimensional turbulent quantum droplets. Phys. Rev. Fluids 10, 064618. Jun 25, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/pj6n-3w6p

arXiv:2501.01771v1 [cond-mat.quant-gas]. Jan 3, 2025.

https://arxiv.org/abs/2501.01771

Also: drop, droplet, droploid, turbulence, vortex, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drop, droplet, droploid, turbulence, vortex, harmonic trap, quantum fluctuations, exotic phases of matter, self-similar nonequilibrium dynamics

# gst: transient and steady-state chaos in dissipative quantum systems.

<< Dissipative quantum chaos plays a central role in the characterization and control of information scrambling, non-unitary evolution, and thermalization, but it still lacks a precise definition. >>

AA << properly restore the quantum-classical correspondence through a dynamical approach based on entanglement entropy and out-of-time-order correlators (OTOCs), which reveal signatures of chaos beyond spectral statistics. Focusing on the open anisotropic Dicke model, (They) identify two distinct regimes: transient chaos, marked by rapid early-time growth of entanglement and OTOCs followed by low saturation values, and steady-state chaos, characterized by high long-time values. >>

AA << introduce a random matrix toy model and show that Ginibre spectral statistics signals short-time chaos rather than steady-state chaos. (Their) results establish entanglement dynamics and OTOCs as reliable diagnostics of dissipative quantum chaos across different timescales. >>

Debabrata Mondal, Lea F. Santos, S. Sinha. Transient and steady-state chaos in dissipative quantum systems. arXiv: 2506.05475v1 [quant-ph]. Jun 5, 2025. 

https://arxiv.org/abs/2506.05475

Also: chaos, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, information scrambling, entropy, chaos, transient chaos, steady-state chaos.

# game: Parrondo's paradox in space-inhomogeneous quantum walks.

<< The term Parrondo's paradox refers to the apparently paradoxical effect whereby two or more dynamics in which a given quantity decreases are combined in such a way that the same quantity increases in the resulting dynamics. >>

AA << show that Parrondo's paradox can occur not only in the case of homogeneous but also in space-inhomogeneous one-dimensional discrete-time quantum walks. >>

<< Moreover, (They) demonstrate that for such quantum walks Parrondo's paradox can affect the time evolution of quantum entanglement differently than it does in the case of homogeneous ones. >>

Zbigniew Walczak, Jarosław H. Bauer. Parrondo's paradox in space-inhomogeneous quantum walks. Phys. Rev. E 111, 064218. Jun 25, 2025.

https://journals.aps.org/pre/abstract/10.1103/k6nn-n6c4

Also: Parrondo, game, in https://www.inkgmr.net/kwrds.html 

Keywords: Parrondo, games

# gst: topological phase transition under infinite randomness

<< In clean and weakly disordered systems, topological and trivial phases having a finite bulk energy gap can transit to each other via a quantum critical point. In presence of strong disorder, both the nature of the phases and the associated criticality can fundamentally change. >>

Here AA << investigate topological properties of a strongly disordered fermionic chain where the bond couplings are drawn from normal probability distributions which are defined by characteristic standard deviations. Using numerical strong disorder renormalization group methods along with analytical techniques, (AA) show that the competition between fluctuation scales renders both the trivial and topological phases gapless with Griffiths like rare regions. >>

<< Moreover, the transition between these phases is solely governed by the fluctuation scales, rather than the means, rendering the critical behavior to be determined by an infinite randomness fixed point with an irrational central charge. (AA) work points to a host of novel topological phases and atypical topological phase transitions which can be realized in systems under strong disorder. >>

Saikat Mondal, Adhip Agarwala. Topological Phase Transition under Infinite Randomness. arXiv: 2506.19913v1 [cond-mat.dis-nn]. Jun 24, 2025.

https://arxiv.org/abs/2506.19913

Also: order, disorder, disorder & fluctuations, random, transition, forms of power, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, order, disorder, disorder & fluctuations, randomness, criticality, transitions, forms of power

FonT: who knows if during some master's courses on the organization and evolution of social enclosures, held by the legendary "Frattocchie School" ( https://it.m.wikipedia.org/wiki/Scuola_delle_Frattocchie ) during the early 80s (but also early 90s) some bizarre theoretician advanced the imaginative, up in the air, absolutely unfounded hypothesis (here it is emphasized: absolutely), about the possibility of an immediate cracking of a social structure due to the action of idiots (?) disguised as idiots until the complete, universal, ontheback breakthrough anzicheforse?

# gst: accelerated first detection in discrete-time quantum walks using sharp restarts.

<< Restart is a common strategy observed in nature that accelerates first-passage processes, and has been extensively studied using classical random walks. In the quantum regime, restart in continuous-time quantum walks (CTQWs) has been shown to expedite the quantum hitting times [Phys. Rev. Lett. 130, 050802 (2023)]. >>

 Here, AA << study how restarting monitored discrete-time quantum walks (DTQWs) affects the quantum hitting times. (They) show that the restarted DTQWs outperform classical random walks in target searches, benefiting from quantum ballistic propagation, a feature shared with their continuous-time counterparts. >>

Kunal Shukla, Riddhi Chatterjee, C. M. Chandrashekar. Accelerated first detection in discrete-time quantum walks using sharp restarts. Phys. Rev. Research 7, 023069. Apr 21, 2025.

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.7.023069

Also: walk, random, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, networks, randomness, walk, random walk, quantum walk, stochasticity, sharp restart.

# gst: when a phase transition could be controlled by a fixed point of infinite disorder

AA << apply a real-space block renormalization group approach to study the critical properties of the random transverse-field Ising spin chain with multispin interactions. First (They) recover the known properties of the traditional model with two-spin interactions by applying the renormalization approach for arbitrary size of the block. For the model with three-spin couplings (They) calculate the critical point and demonstrate that the phase transition is controlled by an infinite disorder fixed point. (AA) have determined the typical correlation-length critical exponent, which seems to be different from that of the random transverse Ising chain with nearest-neighbor couplings. Thus this model represents a new infinite disorder universality class. >>️

Ferenc Iglói, Yu-Cheng Lin. Random quantum Ising model with three-spin couplings. arXiv:2503.18690v1 [cond-mat.dis-nn]. Mar 24, 2025.

https://arxiv.org/abs/2503.18690

Also: disorder, order, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, disorder, order, transition

# qubit: stability of classical shadows under gate-dependent noise

<< Expectation values of observables are routinely estimated using so-called classical shadows—the outcomes of randomized bases measurements on a repeatedly prepared quantum state. In order to trust the accuracy of shadow estimation in practice, it is crucial to understand the behavior of the estimators under realistic noise. >>

<< In this Letter, (AA) prove that any shadow estimation protocol involving Clifford unitaries is stable under gate-dependent noise for observables with bounded stabilizer norm—originally introduced in the context of simulating Clifford circuits. In contrast, (They) demonstrate with concrete examples that estimation of “magic” observables can lead to highly misleading results in the presence of miscalibration errors and a worst case bias scaling exponentially in the system size. >>

AA << further find that so-called robust shadows, aiming at mitigating noise, can introduce a large bias in the presence of gate-dependent noise compared to unmitigated classical shadows. Nevertheless, (AA) guarantee the functioning of robust shadows for a more general noise setting than in previous works. On a technical level, (They) identify average noise channels that affect shadow estimators and allow for a more fine-grained control of noise-induced biases. >>️

Raphael Brieger, Markus Heinrich, et al. Stability of Classical Shadows under Gate-Dependent Noise. Phys. Rev. Lett. 134, 090801. Mar 4, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.090801  arXiv: 2310.19947v3 [quant-ph]. Feb 19, 2025.   https://arxiv.org/abs/2310.19947

Also: qubit, in FonT  https://flashontrack.blogspot.com/search?q=qubit  noise, ai (artificial intell) (bot), in https://www.inkgmr.net/kwrds.html   

Keywords: qubit, noise, realistic noise, shadows, robust shadows

# qubit: communication power of a noisy qubit.

<< A fundamental limitation of quantum communication is that a single qubit can carry at most one bit of classical information. For an important class of quantum communication channels, known as entanglement breaking, this limitation holds even if the sender and receiver share entangled particles. But does this mean that, for the purpose of communicating classical messages, a noisy entanglement-breaking qubit channel can be replaced by a noisy bit channel? >>

Here AA << answer the question in the negative. (They) introduce a game, similar to the Monty Hall problem in classical statistics, where a sender assists a receiver in finding a valuable item (the “prize”) hidden in one of four possible boxes, while avoiding a hazardous item (the “bomb”) hidden in one of the remaining three boxes. (AA) show that no classical strategy using a noisy bit channel can ensure that the bomb is avoided, even if the sender and receiver share arbitrary amounts of randomness. >>

<< In contrast, communication of a qubit through a class of noisy entanglement-breaking channels, which (They) call quantum not channels, allows the players to deterministically avoid the bomb and to find the prize with a guaranteed nonzero probability. >>

AA << findings show that the communication of classical messages through a noisy entanglement-breaking qubit channel assisted by quantum entanglement cannot, in general, be simulated by communication through a noisy bit channel assisted by classical correlations. >>️

Giulio Chiribella, Saptarshi Roy, et al. Communication Power of a Noisy Qubit. Phys. Rev. Lett. 134, 080803. Feb 28, 2025. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.080803     arXiv: 2405.17946v2 [quant-ph]. https://arxiv.org/abs/2405.17946  

Also: qubit, in https://flashontrack.blogspot.com/search?q=qubit  game, in  https://flashontrack.blogspot.com/search?q=game  noise, in  https://flashontrack.blogspot.com/search?q=noise 

Keywords: qubit, games, noise

# gst: necklacelike pattern of vortex bound states

<< A vortex is a topological defect in the superconducting condensate when a magnetic field is applied to a type-II superconductor, (..). Because of the confinement of the quasiparticles by a vortex, it exhibits a circular-shaped pattern of bound states with discrete energy levels, (..) >>

 Here, AA << report a completely new type of vortex pattern which is necklacelike in an iron-based superconductor (..). (AA) theoretical analysis shows that this necklacelike vortex pattern arises primarily from selective off-shell interference between vortex bound states of opposite angular momenta in the presence of rotational symmetry breaking due to disorders. >>

<< This fascinating effect can be observed in a system with a small Fermi energy and wave vector, conditions fortuitously met in (Their) samples. (AA) results not only disclose a novel vortex structure, but also unravel a completely new quantum phenomenon in the superconducting condensate. >>️

Zhiyong Hou, Kailun Chen, et al. Necklacelike Pattern of Vortex Bound States. Phys. Rev. X 15, 011027. Feb 7, 2025.   https://journals.aps.org/prx/abstract/10.1103/PhysRevX.15.011027   arXiv: 2407.08547v1 [cond-mat.supr-con]. Jul 11, 2024.    https://arxiv.org/abs/2407.08547

Also: vortex, disorder, disorder & fluctuations, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, vortex, vortex bound states, symmetry breaking, disorder, disorder & fluctuations, necklacelike patterns

# gst: chaotic billiards inside mixed curvatures

<< The boundary of a billiard system dictates its dynamics, which can be integrable, mixed, or fully chaotic. >>️

This AA study << introduces two such billiards: a bean-shaped billiard and a peanut-shaped billiard, the latter being a variant of Cassini ovals. Unlike traditional chaotic billiards, these systems incorporate both focusing and defocusing regions along their boundaries, with no neutral segments. >>

AA << examine both classical and quantum dynamics of these billiards and observe a strong alignment between the two perspectives. For classical analysis, the billiard flow diagram and billiard map reveal sensitivity to initial conditions, a hallmark of classical chaos. In the quantum domain, (AA) use nearest-neighbour spacing distribution and spectral complexity as statistical measures to characterise chaotic behaviour. >>

<< Both classical and quantum mechanical analysis are in firm agreement with each other. One of the most striking quantum phenomena (They) observe is the eigenfunction scarring (both scars and super-scars). Scarring phenomena serve as a rich visual manifestation of quantum and classical correspondence, and highlight quantum suppression chaos at a local level. >>

Pranaya Pratik Das, Tanmayee Patra, Biplab Ganguli. Manifestations of chaos in billiards: the role of mixed curvature. arXiv: 2501.08839v1 [nlin.CD]. Jan 15, 2025.

https://arxiv.org/abs/2501.08839

Also: billiard, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, billiard, chaos