Article
Materials Science, Multidisciplinary
Korbinian Kottmann, Andreas Haller, Antonio Acin, Grigory E. Astrakharchik, Maciej Lewenstein
Summary: Recent research has identified a new phase separated phase in the extended Bose-Hubbard model in one dimension at integer filling, with superfluid and supersolid parts generated by mechanical instability. Numerical simulations reveal peculiar spatial patterns and characteristics in different phases, which persist in the thermodynamic limit. Furthermore, the low-energy spectrum of the phase can be effectively captured by a spinless Luttinger liquid, with consistent results between different analysis methods.
Article
Optics
Soumyadeep Halder, Subrata Das, Sonjoy Majumder
Summary: The recent realization of a binary dipolar Bose-Einstein condensate opens up new possibilities for studying quantum droplets and supersolids in binary mixtures. In this study, the ground-state phases and dynamics of a Dy-Dy mixture are investigated using three-dimensional numerical simulations. Various interesting phases, including single-droplet, multiple-droplets, doubly supersolid, and superfluid states, are observed in both miscible and immiscible phases. The dynamics across phase boundaries are also explored, showing abrupt changes in phase and the formation of metastable states.
Article
Multidisciplinary Sciences
Charles Peretti, Jeremy Vessaire, Emeric Durozoy, Mathieu Gibert
Summary: This article demonstrates the visualization and quantification of quantum vortices in a stationary rotating superfluid bucket and verifies Feynman's rule. The researchers also induce different effects by adjusting the heat flux, providing a foundation for studying quantum turbulence in rotating He-4.
Article
Physics, Multidisciplinary
Ya-Hui Zhang, D. N. Sheng, Ashvin Vishwanath
Summary: The paper proposes using moire bilayers as a platform to stabilize and detect exotic quantum phases. In the small distance limit, an SU(4) spin can be formed by combining layer pseudospin and real spin. By tuning a ring exchange term K, different phases including symmetric crystallized phase, chiral spin liquid, and exciton supersolid phases can be predicted. Evidences of these phases can be obtained by measuring pseudo-spin transport in the counter-flow channel.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Ya-Hui Zhang, D. N. Sheng, Ashvin Vishwanath
Summary: Researches propose a platform of moire bilayer where exotic quantum phases can be stabilized and detected electrically, forming SU(4) spin through interlayer coupling, and finding SU(4) symmetric crystallized phase and chiral spin liquid at balanced filling.
PHYSICAL REVIEW LETTERS
(2021)
Article
Mechanics
Anthony M. Guenault, Peter V. E. McClintock, Malcolm Poole, Roch Schanen, Viktor Tsepelin, Dmitry E. Zmeev, David Schmoranzer, William F. Joe Vinen, Deepak Garg, Kalpana Devi
Summary: We introduce a low-frequency torsional oscillator suitable for studies of quantum fluids and solids. It operates at frequencies of similar to 100 Hz, achieves velocities of several cm s(-1,) and exhibits a quality factor of Q similar or equal to 3 x 104.
Article
Physics, Multidisciplinary
Zhi-Da Bai, Vladimir I. Korobov, Zong-Chao Yan, Ting-Yun Shi, Zhen-Xiang Zhong
Summary: The transition frequency of (n, l) = (17, 16) -> (16, 15) in pionic helium-4 is calculated with high accuracy, including relativistic and quantum electrodynamic corrections. The calculations significantly improve the previous theoretical values and estimate the collisional effects between pionic helium and target helium on the transition frequencies. This study has the potential to greatly improve the value of the pi(-) mass once measurements reach the ppb level.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Lionel Djadaojee, Jules Grucker
Summary: We measured the Brillouin frequencies of acoustically driven metastable states of superfluid He-4 at T similar to 1 K and found that thermal effects or vortices can play a significant role in the cavitation process.
PHYSICAL REVIEW LETTERS
(2022)
Article
Automation & Control Systems
Mohsen Zafarani, Bashir H. Jafari, Bilal Akin
Summary: In this article, the lateral and torsional vibrations in multistack rotor induction motors are modeled in the same framework to analyze the precursors in the current waveform. A lumped mass-spring model is used to calculate natural frequencies and torsional-mode shapes of the mechanical system, while winding function theory is employed to mimic the effects of lateral vibrations on motor inductances. Experimental results are presented and compared with analytical results to validate the modeling approach.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Physics, Multidisciplinary
S. M. Roccuzzo, S. Stringari, A. Recati
Summary: We investigate the density distributions of a dipolar Bose-Einstein condensed gas confined in a box potential, focusing on the effects of supersolidity. The ground-state density exhibits a depletion in the bulk region and an accumulation of atoms near the walls due to the competition between attractive and repulsive forces. In a quasi-two-dimensional geometry, we observe a ringlike configuration near the boundary of the box, indicating supersolid and crystal effects. In the case of square box trapping, density oscillations along the edges resemble quasi-one-dimensional configurations. Supersolidity can also be observed in the bulk region for large atom numbers, reflecting the symmetry of the confining potential.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
T. Bland, E. Poli, C. Politi, L. Klaus, M. A. Norcia, F. Ferlaino, L. Santos, R. N. Bisset
Summary: A robust supersolid state can be formed in a two-dimensional system by directly evaporative cooling into the supersolid phase. The research provides a theoretical basis for the formation process of two-dimensional supersolids and defines a practical path to the formation of large two-dimensional supersolid arrays.
PHYSICAL REVIEW LETTERS
(2022)
Article
Mechanics
Caiqian Dong, Xiaoyu Cui, Shaoshuai Liu, Zhenhua Jiang, Jiantang Song, Yinong Wu, Lihao Lu
Summary: The physical characteristics of choked helium significantly affect the heat and mass transfer in helium cryogenic systems. This study numerically calculates, analyzes, and experimentally validates the choked features of helium below the liquid hydrogen temperature region. The experimental results match well with the theoretical models, although there are some differences.
Article
Chemistry, Physical
Arthur M. Halpern
Summary: A new equation of state is used to calculate the thermochemical properties of helium-4 dimerization and trimerization between 3.0 and 10.0 K. The calculations show significant populations of dimer and trimer at sufficiently low temperatures. The results from statistical thermodynamic calculations are qualitatively consistent with those obtained from EOS calculations.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Multidisciplinary Sciences
Julian J. Krauth, Karsten Schuhmann, Marwan Abdou Ahmed, Fernando D. Amaro, Pedro Amaro, Francois Biraben, Tzu-Ling Chen, Daniel S. Covita, Andreas J. Dax, Marc Diepold, Luis M. P. Fernandes, Beatrice Franke, Sandrine Galtier, Andrea L. Gouvea, Johannes Goetzfried, Thomas Graf, Theodor W. Haensch, Jens Hartmann, Malte Hildebrandt, Paul Indelicato, Lucile Julien, Klaus Kirch, Andreas Knecht, Yi-Wei Liu, Jorge Machado, Cristina M. B. Monteiro, Francoise Mulhauser, Boris Naar, Tobias Nebel, Francois Nez, Joaquim M. F. dos Santos, Jose Paulo Santos, Csilla I. Szabo, David Taqqu, Joao F. C. A. Veloso, Jan Vogelsang, Andreas Voss, Birgit Weichelt, Randolf Pohl, Aldo Antognini, Franz Kottmann
Summary: The energy levels of hydrogen-like atomic systems can be calculated with great precision, which can be used to study nuclear structure. Through measuring the root-mean-square charge radius of the proton and comparing it with the value from electron scattering, it provides a benchmark for few-nucleon theories, lattice quantum chromodynamics, and electron scattering. The agreement also constrains several beyond-standard-model theories proposed to explain the proton-radius puzzle, establishing spectroscopy of light muonic atoms and ions as a precise tool for studies of nuclear properties.
Article
Computer Science, Information Systems
Ahmed Fathy Abouzeid, Juan M. Guerrero, Iban Vicente-Makazaga, Iker Muniategui-Aspiazu, Aitor Endemano-Isasi, Fernando Briz
Summary: This paper proposes a novel torsional vibration suppression method using a Proportional-Resonant (PR) controller. The method does not require adding new sensors to the wheelset and is insensitive to mechanical drive-train parameter variation. It provides reduced sensitivity to slip velocities and wheel-rail conditions without compromising the traction capability.