@article{22100, abstract = {Spin mixtures of degenerate fermions are a cornerstone of quantum many-body physics, enabling superfluidity, polarons, and rich spin dynamics through s-wave scattering resonances. Combining them with strong, long-range dipolar interactions provides highly flexible control schemes promising even more exotic quantum phases. Recently, microwave shielding gave access to spin-polarized degenerate samples of dipolar fermionic molecules, where tunable p-wave interactions were enabled by field-linked resonances available only by compromising the shielding (due to experimental limitations). Here, we study the scattering properties of a fermionic dipolar spin mixture and show that a universal s-wave resonance is readily accessible without compromising the shielding. We develop a universal description of the tunable s-wave interaction and weakly bound tetratomic states based on the microwave-field parameters. The s-wave resonance paves the way to stable, controllable and strongly-interacting dipolar spin mixtures of deeply degenerate fermions and supports favorable conditions to reach this regime via evaporative cooling.}, author = {Li, Jinglun and Koutentakis, Georgios and Hrast, Mateja and Lemeshko, Mikhail and Schindewolf, Andreas and Al Hyder, Ragheed}, issn = {2399-3650}, journal = {Communications Physics}, publisher = {Springer Nature}, title = {{Tunable field-linked s-wave interactions in dipolar fermi mixtures}}, doi = {10.1038/s42005-026-02578-8}, volume = {9}, year = {2026}, } @article{21149, abstract = {We present a general theoretical framework for helical dichroism (HD), establishing an explicit link between chiral resolution and orbital angular momentum (OAM) exchange in light–matter interaction. Tracing microscopic mechanisms of the OAM transfer, we derive rotational selection rules, which establish that HD emerges only from the spin–orbit coupling of light, even for beams without the far-field OAM. Our findings refine the conditions for observing HD, provide a tool to re-examine the outcome of prior experiments, and guide future designs for chiral sensing with structured light.}, author = {Hrast, Mateja and Koutentakis, Georgios and Maslov, Mikhail and Lemeshko, Mikhail}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {5}, publisher = {American Physical Society}, title = {{Bottom-up analysis of rovibrational helical dichroism}}, doi = {10.1103/fkf1-1jml}, volume = {136}, year = {2026}, } @article{21273, abstract = {In this paper we examine how porosity fluctuations affect the hydrodynamic permeability of a porous matrix or membrane. We introduce a fluctuating Darcy model, which couples the Navier-Stokes equation to the space- and time-dependent porosity fluctuations via a Darcy friction term. Using a perturbative approach, a Dyson equation for hydrodynamic fluctuations is derived and solved to express the permeability in terms of the matrix fluctuation spectrum. Surprisingly, the model reveals strong modifications of the fluid permeability in fluctuating matrices compared to static ones. Applications to various matrix excitation models, the breathing matrix, phonons, and active forcing, highlight the significant influence of matrix fluctuations on fluid transport, offering insights for optimizing membrane design for separation applications.}, author = {Dombret, Albert and Sutter, Adrien and Coquinot, Baptiste and Kavokine, Nikita and Coasne, Benoit and Bocquet, Lydéric}, issn = {2469-990X}, journal = {Physical Review Fluids}, number = {1}, publisher = {American Physical Society}, title = {{Hydrodynamic permeability of fluctuating porous membranes}}, doi = {10.1103/m8h6-1wfk}, volume = {11}, year = {2026}, } @article{21373, abstract = {Cold atom experiments show that a mobile impurity particle immersed in a weakly interacting Bose-Einstein condensate forms a well-defined quasiparticle (Bose polaron) for weak to moderate impurity-boson interaction strengths, whereas a significant line broadening is consistently observed for strong interactions. Motivated by this, we introduce a phenomenological theory based on the assumption that the most relevant states are characterized by the impurity correlated with at most one boson, since they have the largest overlap with the uncorrelated states to which the most common experimental probes couple. These experimentally relevant states can, however, decay to lower energy states characterized by correlations involving multiple bosons, and we model this using a minimal variational wave function combined with a complex impurity-boson interaction strength. We first motivate this approach by comparing to a more elaborate theory that includes correlations with up to two bosons. Our phenomenological model is shown to recover the main results of two recent experiments probing both the spectral and the nonequilibrium properties of the Bose polaron. Our work offers an intuitive framework for analyzing experimental data and highlights the importance of understanding the complicated problem of the Bose polaron decay in a many-body setting.}, author = {Al Hyder, Ragheed and Bruun, G. M. and Pohl, T. and Lemeshko, Mikhail and Volosniev, Artem}, issn = {2643-1564}, journal = {Physical Review Research}, publisher = {American Physical Society}, title = {{Phenomenological model of decaying Bose polarons}}, doi = {10.1103/16dk-5dgx}, volume = {8}, year = {2026}, } @article{21470, abstract = {Despite its pivotal role in optical manipulation, high capacity communications, and quantum information, a general measure of orbital angular momentum (OAM) in structured light remains elusive. In optical fields, where multiple vortices coexist, the local nature of vortex OAM and the absence of a common rotation axis make the total OAM of the field difficult to quantify. Here, we introduce the R index—a metric that captures the intrinsic OAM content of any structured optical field, from pure Laguerre–Gaussian modes to arbitrary multi vortex superpositions. Not only does this metric quantify the total OAM, it also assesses field purity, providing insight into the fidelity and robustness of the OAM generation. By unifying OAM characterization into a single figure of merit, the R index enables direct comparison across diverse beam profiles and facilitates the identification of optimal configurations for both foundational studies and applied technologies.}, author = {Bahl, Monika and Koutentakis, Georgios and Maslov, Mikhail and Jungnickel, Tom and Gaßen, Timo and Lemeshko, Mikhail and Heckl, Oliver H.}, issn = {2515-7647}, journal = {Journal of Physics: Photonics}, number = {1}, publisher = {IOP Publishing}, title = {{The R-index: A universal metric for evaluating OAM content and mode purity in optical fields}}, doi = {10.1088/2515-7647/ae3506}, volume = {8}, year = {2026}, } @article{21660, abstract = {Kapitza-Dirac scattering, the diffraction of matter waves from a standing light field, is widely utilized in ultracold gases, but its behavior in the strongly interacting regime is an open question. Here, we develop a numerically exact two-body description of Kapitza-Dirac scattering for two contact-interacting atoms in a one-dimensional harmonic trap subjected to a pulsed optical lattice, enabling us to obtain the numerically exact dynamics. We map how interaction strength, lattice depth, lattice wave number, and pulse duration reshape the diffraction pattern, leading to an interaction-dependent population redistribution in real and momentum space. By comparing the exact dynamics to an impulsive sudden-approximation description, we delineate the parameter regimes where it remains accurate and those, notably at strong attraction and small lattice wave number, where it fails. Our results provide a controlled few-body benchmark for interacting Kapitza-Dirac scattering and quantitative guidance for Kapitza-Dirac-based probes of ultracold atomic systems.}, author = {Becker, A. and Koutentakis, Georgios and Schmelcher, P.}, issn = {2643-1564}, journal = {Physical Review Research}, publisher = {American Physical Society}, title = {{Two-body Kapitza-Dirac scattering of one-dimensional ultracold atoms}}, doi = {10.1103/rdsn-stlq}, volume = {8}, year = {2026}, } @article{21840, abstract = {The transport properties of nanofluidic channels are usually studied under constant (DC) voltage or pressure driving. However, the frequency response under sinusoidal (AC) drivings offers rich insights into the time-dependent transport mechanisms. Inspired by recent electrochemical approaches, we investigate the couplings between ionic and electronic transport under AC driving. We show that conduction electrons of the channel walls participate in ionic current via capacitive electrochemical coupling, defining a critical frequency and length scale where electron-dominated conductivity emerges. We further analyze how electron–ion coupling modifies electro-osmotic flows and demonstrate that fluctuation-induced momentum transfer between the electrolyte and wall electrons produces distinct AC transport signatures, depending on the charge carrier polarity. Altogether, we establish a frequency-dependent transport matrix that couples ionic, electronic, and hydrodynamic flows. These findings establish AC nanofluidic transport as a powerful probe of interfacial phenomena under confinement and suggest new directions for engineering nanofluidic functionalities through electron–electrolyte coupling.}, author = {Coquinot, Baptiste and Lizée, Mathieu and Bocquet, Lydéric and Kavokine, Nikita}, issn = {1089-7690}, journal = {The Journal of Chemical Physics}, number = {13}, publisher = {AIP Publishing}, title = {{Electron–electrolyte coupling in AC transport through nanofluidic channels}}, doi = {10.1063/5.0313352}, volume = {164}, year = {2026}, } @article{22145, abstract = {An in-operando electro-intercalation method for the on-chip synthesis of alkali-metal-intercalated materials and their Raman spectroscopic and transport characterization in ultrahigh vacuum (UHV) is developed. We apply this method to synthesize fulleride superconductors via Rb+ intercalation into a C60 film. During the intercalation, we monitor the stoichiometry via UHV-Raman spectroscopy and probe superconductivity via transport measurements. An increase of the superconducting transition temperature from 7.0 K to 14.5 K is observed when the stoichiometry is tuned from Rb2.7C60 to Rb3C60. In our experiment, an ionic Rb+ flux into the host material is induced by an applied electronic current via a Butler–Volmer-type mechanism. Electro-intercalation captivates through improved stoichiometric precision, the ability to smoothly vary stoichiometry via duration of current application, and the absence of a lower limit of the volume of the host material. It represents a powerful concept for the on-chip synthesis of intercalated materials, battery research, and beyond.}, author = {Shchukin, Konstantin P. and Gallego Lacey, Oliver N. and Coquinot, Baptiste and Jakowski, Jacek and Huang, Jingsong and Staudenmayer, Patrik and Falke, Yannic and Pandeya, Ram Prakash and Grüneis, Alexander}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {fulleride, intercalation, alkali metal, superconductivity, Raman}, number = {24}, pages = {17360--17372}, publisher = {American Chemical Society}, title = {{On-chip tuning of superconductivity in fullerides via current-driven Rb+ intercalation}}, doi = {10.1021/acsnano.6c02466}, volume = {20}, year = {2026}, } @article{22304, abstract = {We derive an analog of the Lellouch-Lüscher (LL) relation for few-body bosonic systems, linking few-body scattering loss rates to the energies and widths of the corresponding harmonically trapped few-body states. Three-body numerical simulations show that the LL relation applies across a broad range of interaction strengths and energies and allows the determination of scattering rates within a single partial wave. Our Letter establishes a robust theoretical framework for understanding the role of the finite-volume effect in few-body observables in optical lattice and tweezer experiments, enabling precise determination of multibody scattering rates.}, author = {Li, Jinglun and Julienne, Paul S. and Denschlag, Johannes Hecker and D’Incao, José P.}, issn = {1079-7114}, journal = {Physical Review Letters}, number = {20}, publisher = {American Physical Society}, title = {{Lellouch-Lüscher relation for ultracold few-atom systems under confinement}}, doi = {10.1103/pzlp-7k8d}, volume = {136}, year = {2026}, } @article{22308, abstract = {This article is a collection of contributions from speakers at the 2025 DEAMN workshop at the Majorana Centre in Erice. Not ordinary contributions to a conference proceeding, this gives a new and different perspective on the work done by the workshop participants.}, author = {Hansen, Klavs and Kresin, Vitaly and Al Hyder, Ragheed and Lemeshko, Mikhail and Fárník, Michal and Fedor, Juraj and Ferrari, Piero and Worutowicz, Laura X. and Louwerse, Rick J. and Kiawi, Denis and Waters, Laurens B. F. M. and Lang, Sandra M. and Bakker, Joost M. and von Issendorff, Bernd and Kong, Wei and Mehmel, Jannik and Schäfer, Rolf and Pedalino, Sebastian and Ramírez-Galindo, Bruno E. and Ferstl, Richard and Sindelar, Severin and Gerlich, Stefan and Arndt, Markus and Sayres, Scott G. and Wang, Lai-Sheng}, issn = {1434-6079}, journal = {The European Physical Journal D}, number = {5}, publisher = {Springer Nature}, title = {{Reflections on future problems in cluster science}}, doi = {10.1140/epjd/s10053-026-01126-x}, volume = {80}, year = {2026}, } @article{21009, abstract = {We demonstrate that periodically driven quantum rotors provide a promising and broadly applicable platform to implement multigap topological phases, where groups of bands can acquire topological invariants due to non-Abelian braiding of band degeneracies. By adiabatically varying the periodic kicks to the rotor we find nodal-line braiding, which causes sign flips of topological charges of band nodes and can prevent them from annihilating, indicated by nonzero values of the patch Euler class. In particular, we report on the emergence of an anomalous Dirac string phase arising in the strongly driven regime, a truly out-of-equilibrium phase of the quantum rotor. This phase emanates from braiding processes involving all (quasienergy) gaps and manifests itself with edge states at zero angular momentum. Our results reveal direct applications in state-of-the-art experiments of quantum rotors, such as linear molecules driven by periodic far-off-resonant laser pulses or artificial quantum rotors in optical lattices, whose extensive versatility offers precise modification and observation of novel non-Abelian topological properties.}, author = {Karle, Volker and Lemeshko, Mikhail and Bouhon, Adrien and Slager, Robert-Jan and Ünal, F. Nur}, issn = {2469-9934}, journal = {Physical Review A}, number = {1}, publisher = {American Physical Society}, title = {{Anomalous multigap topological phases in periodically driven quantum rotors}}, doi = {10.1103/db9d-9bns}, volume = {113}, year = {2026}, } @article{22613, abstract = {A phase plate has long been sought in transmission electron microscopy (TEM) to maximize the image contrast of weakly-scattering objects like biomolecules. The laser phase plate (LPP) has recently demonstrated that an amplified, focused laser standing wave reliably phase shifts the electron beam, achieving phase-contrast TEM. Building on the single-beam LPP, here we introduce the crossed laser phase plate (XLPP): two laser standing waves which intersect in the diffraction plane. We present a theoretical model for the XLPP inside the microscope and show that, relative to the original LPP, it increases information transfer at low spatial frequencies while suppressing ghost images formed by Kapitza-Dirac diffraction. We also present a simple acquisition scheme, enabled by the XLPP, which further suppresses ghosts. Finally, we discuss practical considerations of XLPP design and show experimental results from a prototype. The results of this study chart the course for future developments of LPP hardware.}, author = {Petrov, Petar N and Zhang, Jessie T. and Axelrod, Jeremy J. and Olshin, Pavel K. and Müller, Holger}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Crossed laser phase plates for transmission electron microscopy}}, doi = {10.1038/s41467-026-74060-6}, volume = {17}, year = {2026}, } @article{22365, abstract = {Phase plates can, in principle, overcome the poor image contrast in cryo–electron microscopy (cryo-EM) and the resulting limits on the structural reconstruction of small proteins. However, previous designs have been unstable and compromised the high-resolution signal and have thus been unable to surpass results achieved by standard cryo-EM. Here, we show that the laser phase plate (LPP), installed in a modern, custom Titan Krios microscope, enhances the resolution in single-particle reconstruction of small proteins by improving specimen-motion correction and recovery of information from the early frames, as well as particle visualization, three-dimensional classification, and alignment. These advances use standard defocus ranges and reconstruction procedures but open the door to LPP-tailored protocols, offering further improvements by leveraging the LPP demonstrated here.}, author = {Petrov, Petar N and Zhang, Jessie T. and Remis, Jonathan and Axelrod, Jeremy J. and Cheng, Hang and Cooper, Eric S. and Hicklin, Ian K. and Sandhaus, Shahar and Schnurr, Cooper and Glaeser, Robert M. and Müller, Holger}, issn = {1095-9203}, journal = {Science}, number = {6807}, pages = {195--196}, publisher = {AAAS}, title = {{Laser phase plate improves structure determination of small proteins by cryo-EM}}, doi = {10.1126/science.aeh0665}, volume = {393}, year = {2026}, } @article{22952, abstract = {Mechanosensitive ion transport plays a central role in enabling living systems to perceive and adapt to their environment through the deformation of soft, embedded ion channels. In this work, we demonstrate that ion transport within a two-dimensional graphite nanoslit can be rationally engineered to achieve a bipolar, pressure-sensitive response without any structural deformation. The mechanosensitivity arises from the selective charging of one channel inlet, which acts as a reversible source of mobile charge carriers. These excess ions can then be advected in or out of the channel by the pressure-driven water flow, thereby modulating the ionic conductance. This mechanism is captured through a comprehensive electrohydrodynamic model that analytically accounts for coupled diffusion, convection, surface transport, diffusio-osmosis, and interfacial slippage, both inside and outside the nanoslit. The theoretical framework quantitatively reproduces the experimental data, showing that a simple surface charge pattern can give rise to complex, pressure-dependent conductance. These findings reveal how rich nonlinear couplings at the nanoscale can be harnessed to design adaptive, bioinspired nanofluidic systems, exemplified here by ionic pressure sensors.}, author = {Lizée, Mathieu and Zhang, Zhijia and Coquinot, Baptiste and Yang, Qian and Bocquet, Lydéric}, issn = {2375-2548}, journal = {Science Advances}, number = {31}, publisher = {AAAS}, title = {{Architecting mechanosensitive nanofluidic transport in graphite nanoslits}}, doi = {10.1126/sciadv.aed4451}, volume = {12}, year = {2026}, } @article{22976, abstract = {The influence of chiral molecular potentials on phase-coherent transport in superconducting Josephson junctions is investigated. Within a Bogoliubov–de Gennes tight-binding framework, a superconducting-normal-superconducting (SNS) junction functionalized by adsorbed chiral molecules is modeled, where electrostatic gradients generated by the molecules induce spin-orbit coupling in the normal region. The equilibrium charge current-phase relation is found to remain largely insensitive to molecular chirality in symmetric, zero-field configurations. In contrast, the spin-polarized equilibrium current exhibits a pronounced chirality-dependent response, with opposite enantiomers producing distinct and anisotropic spin-polarized Josephson currents. The resulting handedness contrast can be enhanced through control parameters such as molecular orientation and the strength of the induced spin-orbit coupling. The temperature dependence of these currents further shows that the chirality-dependent signatures persist across a range of temperatures well below the superconducting critical temperature. These results identify Josephson interferometry as a phase-sensitive setting for probing chirality-dependent spin structure and highlight spin-polarized superconducting transport as a controlled route toward integrating chiral molecular functionality into superconducting spintronic devices.}, author = {Kuliashov, Oleg and Cappellaro, Alberto and Millo, Oded and Paltiel, Yossi and Lemeshko, Mikhail and Al Hyder, Ragheed}, issn = {2469-9969}, journal = {Physical Review B}, number = {15}, publisher = {American Physical Society}, title = {{Supercurrents in Josephson junctions with chiral molecular potentials}}, doi = {10.1103/s1jn-fq4d}, volume = {114}, year = {2026}, } @article{23002, abstract = {We investigate the nonequilibrium dynamics of core-hole excitations in a one-dimensional fermionic few-body system consisting of a spin-polarized Fermi bath coupled to a single heavy mobile impurity. The bath is initially prepared in a particle-hole configuration by emptying a selected bath single-particle orbital, while the impurity is displaced with respect to the center of the bath confinement potential. The quench dynamics are initialized by suddenly switching on the impurity-bath interaction. To resolve the resulting dynamics, we combine two complementary ab initio approaches, namely, the MultiLayer MultiConfiguration Time-Dependent Hartree method for mixtures and a multichannel Born-Oppenheimer framework. We show that the postquench response is governed by the interaction strength, impurity confinement, mass imbalance, and the location of the initially prepared hole within the Fermi sea. The density evolution and impurity center-of-mass motion reveal a competition between mixing and demixing of impurity and bath, while the von Neumann entropy demonstrates the buildup of pronounced many-body correlations. Most importantly, the occupation dynamics of the initially emptied orbital identifies deep core holes as substantially more robust against refilling than bulk or edge vacancies. Our results establish core-hole excitations as robust dynamical many-body features in trapped ultracold fermions and provide a controlled route toward probing orthogonality response, correlation buildup, and hole refilling in real time.}, author = {Becker, A. and Koutentakis, Georgios and Schmelcher, P}, issn = {2643-1564}, journal = {Physical Review Research}, number = {3}, publisher = {American Physical Society}, title = {{Core-hole excitation dynamics of one-dimensional ultracold trapped fermions}}, doi = {10.1103/njcx-z6np}, volume = {8}, year = {2026}, } @inproceedings{23055, abstract = {We report progress toward strong electric-dipole coupling of polar molecules in cryogenic crystals to superconducting microwave resonators for hybrid quantum computing. We detect crystal-shifted inversion transitions of ammonia in neon using a multimode resonator.}, author = {De Zordo, Nikolaus and Borja Espinosa, Carla N and Al Hyder, Ragheed and Li, Jinglun and Kersten, Wenzel and Kanagin, Andrew and Koutentakis, Georgios and Kluibenschedl, Florian and Lemeshko, Mikhail and Fink, Johannes M and Schmiedmayer, Jörg and Redchenko, Elena}, booktitle = {Quantum 2.0 Conference and Exhibition}, isbn = {9781957171616}, location = {Glasgow, United Kingdom}, publisher = {Optica Publishing Group}, title = {{Detecting polar molecules with superconducting microwave resonators}}, year = {2026}, } @article{18821, abstract = {Even though the one-dimensional contact interaction requires no regularization, renormalization methods have been shown to improve the convergence of numerical calculations considerably. In this work, we compare and contrast these methods: “the running coupling constant” where the two-body ground-state energy is used as a renormalization condition, and two effective interaction approaches that include information about the ground as well as excited states. In particular, we calculate the energies and densities of few-fermion systems in a harmonic oscillator with the configuration-interaction method and compare the results based upon renormalized and bare interactions. We find that the use of the running coupling constant instead of the bare interaction improves convergence significantly. A comparison with an effective interaction, which is designed to reproduce the relative part of the energy spectrum of two particles, showed a similar improvement. The effective interaction provides an additional improvement if the center-of-mass excitations are included in the construction. Finally, we discuss the transformation of observables alongside the renormalization of the potential, and demonstrate that this might be an essential ingredient for accurate numerical calculations.}, author = {Brauneis, Fabian and Hammer, Hans Werner and Reimann, Stephanie M. and Volosniev, Artem}, issn = {2469-9934}, journal = {Physical Review A}, number = {1}, publisher = {American Physical Society}, title = {{Comparison of renormalized interactions using one-dimensional few-body systems as a testbed}}, doi = {10.1103/PhysRevA.111.013303}, volume = {111}, year = {2025}, } @article{19276, abstract = {Impurity motion in a many-body environment has been a central issue in the field of low-temperature physics for decades. In bosonic quantum fluids, the onset of a drag force experienced by point-like objects is due to collective environment excitations, driven by the exchange of linear momentum between the impurity and the many-body bath. In this work we consider a rotating impurity, with the aim of exploring how angular momentum is exchanged with the surrounding bosonic environment. In order to elucidate these issues, we employ a quasiparticle approach based on the angulon theory, which allows us to effectively deal with the non-trivial algebra of quantized angular momentum in the presence of a many-body environment. We uncover how impurity dressing by environmental excitations can establish an exchange channel, whose effectiveness crucially depends on the initial state of the impurity. Remarkably, we find that there is a critical value of initial angular momentum, above which this channel effectively freezes.}, author = {Cappellaro, Alberto and Bighin, Giacomo and Cherepanov, Igor and Lemeshko, Mikhail}, issn = {1089-7690}, journal = {Journal of Chemical Physics}, number = {7}, publisher = {AIP Publishing}, title = {{Environment-limited transfer of angular momentum in Bose liquids}}, doi = {10.1063/5.0253451}, volume = {162}, year = {2025}, } @article{19371, abstract = {We investigate a molecular quantum rotor in a two-dimensional Bose-Einstein condensate. The focus is on studying the angulon quasiparticle concept in the crossover from few- to many-body physics. To this end, we formulate the problem in real space and solve it with a mean-field approach in the frame co-rotating with the impurity. We show that the system starts to feature angulon characteristics when the size of the bosonic cloud is large enough to screen the rotor. More importantly, we demonstrate the departure from the angulon picture for large system sizes or large angular momenta where the properties of the system are determined by collective excitations of the Bose gas.}, author = {Suchorowski, Michał and Badamshina, Alina and Lemeshko, Mikhail and Tomza, Michał and Volosniev, Artem}, issn = {2542-4653}, journal = {SciPost Physics}, number = {2}, publisher = {SciPost Foundation}, title = {{Quantum rotor in a two-dimensional mesoscopic Bose gas}}, doi = {10.21468/SciPostPhys.18.2.059}, volume = {18}, year = {2025}, }