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Full-Text Articles in Physical Sciences and Mathematics

Temperature Evolution Of Domains And Intradomain Chirality In 1t- Tas2, Boning Yu, Ghilles Ainouche, Manoj Singh, Bishnu Sharma, James Huber, Michael Boyer Sep 2023

Temperature Evolution Of Domains And Intradomain Chirality In 1t- Tas2, Boning Yu, Ghilles Ainouche, Manoj Singh, Bishnu Sharma, James Huber, Michael Boyer

Physics

We use scanning tunneling microscopy to study the temperature evolution of the atomic-scale properties of the nearly commensurate charge density wave (NC-CDW) state of the low-dimensional material 1T-TaS2. Our measurements at 203, 300, and 354 K, roughly spanning the temperature range of the NC-CDW state, show that while the average CDW periodicity is temperature independent, domaining and the local evolution of the CDW lattice within a domain are temperature dependent. Further, we characterize the temperature evolution of the displacement field associated with the recently discovered intradomain chirality of the NC-CDW state by calculating the local rotation vector. Intradomain chirality throughout …


Dynamics Of Magnetoelastic Robots In Water-Saturated Granular Beds, Animesh Biswas, Trinh Huynh, Balaram Desai, Max Moss, Arshad Kudrolli Sep 2023

Dynamics Of Magnetoelastic Robots In Water-Saturated Granular Beds, Animesh Biswas, Trinh Huynh, Balaram Desai, Max Moss, Arshad Kudrolli

Physics

We investigate the dynamics of a magnetoelastic robot with a dipolar magnetic head and a slender elastic body as it performs undulatory strokes and burrows through water-saturated granular beds. The robot is actuated by an oscillating magnetic field and moves forward when the stroke amplitude increases above a critical threshold. By visualizing the medium, we show that the undulating body fluidizes the bed, resulting in the appearance of a dynamic burrow, which rapidly closes in behind the moving robot as the medium loses energy. We investigate the applicability of Lighthill's elongated body theory of fish locomotion, and estimate the contribution …


Cluster Scaling And Critical Points: A Cautionary Tale, W. Klein, Harvey Gould, Sakib Matin Sep 2023

Cluster Scaling And Critical Points: A Cautionary Tale, W. Klein, Harvey Gould, Sakib Matin

Physics

Many systems in nature are conjectured to exist at a critical point, including the brain and earthquake faults. The primary reason for this conjecture is that the distribution of clusters (avalanches of firing neurons in the brain or regions of slip in earthquake faults) can be described by a power law. Because there are other mechanisms such as 1/f noise that can produce power laws, other criteria that the cluster critical exponents must satisfy can be used to conclude whether or not the observed power-law behavior indicates an underlying critical point rather than an alternate mechanism. We show how a …


Computational Model Of Twisted Elastic Ribbons, Madelyn Leembruggen, Jovana Andrejevic, Arshad Kudrolli, Chris H. Rycroft Jul 2023

Computational Model Of Twisted Elastic Ribbons, Madelyn Leembruggen, Jovana Andrejevic, Arshad Kudrolli, Chris H. Rycroft

Physics

We develop an irregular lattice mass-spring model to simulate and study the deformation modes of a thin elastic ribbon as a function of applied end-to-end twist and tension. Our simulations reproduce all reported experimentally observed modes, including transitions from helicoids to longitudinal wrinkles, creased helicoids and loops with self-contact, and transverse wrinkles to accordion self-folds. Our simulations also show that the twist angles at which the primary longitudinal and transverse wrinkles appear are well described by various analyses of the Föppl-von Kármán equations, but the characteristic wavelength of the longitudinal wrinkles has a more complex relationship to applied tension than …


Density-Mediated Spin Correlations Drive Edge-To-Bulk Flow Transition In Active Chiral Matter, Alexander P. Petroff, Christopher Whittington, Arshad Kudrolli Jul 2023

Density-Mediated Spin Correlations Drive Edge-To-Bulk Flow Transition In Active Chiral Matter, Alexander P. Petroff, Christopher Whittington, Arshad Kudrolli

Physics

We demonstrate that edge currents develop in active chiral matter due to boundary shielding over a wide range of densities corresponding to a gas, fluid, and crystal. The system is composed of spinning disk-shaped grains with chirally arranged tilted legs confined in a circular vibrating chamber. The edge currents are shown to increasingly drive circulating bulk flows with area fraction as percolating clusters develop due to increasing spin-coupling between neighbors mediated by frictional contacts. Edge currents are observed even in the dilute limit. While, at low area fraction, the average flux vanishes except within a distance that is of the …


Quantum Phases Of Lattice Dipolar Bosons Coupled To A High-Finesse Cavity, Yaghmorassene Hebib, Chao Zhang, Jin Yang, Barbara Capogrosso-Sansone May 2023

Quantum Phases Of Lattice Dipolar Bosons Coupled To A High-Finesse Cavity, Yaghmorassene Hebib, Chao Zhang, Jin Yang, Barbara Capogrosso-Sansone

Physics

Two types of long-range interactions, dipolar interaction and cavity-mediated interaction, lead to exotic quantum phases. Both interactions were realized and observed in optical lattice setups. Here, we study quantum phases of dipolar bosons trapped in optical lattices and coupled to a high-finesse cavity where both dipolar interaction and cavity-mediated interaction coexist. We perform quantum Monte Carlo simulations and find that the checkerboard solid is enhanced and the checkerboard supersolid phase can exist in a wide range of densities (e.g., 0.27≲n≲0.73). Our unbiased numerical results suggest that both solid and supersolid phases can be achieved experimentally with magnetic atoms coupled to …


Superconductivity And Fermi Surface Studies Of Β″-(Bedt-Ttf)2[(H2o)(Nh4)2cr(C2o4)3]·18-Crown-6, Brett Laramee, Raju Ghimire, David Graf, Lee Martin, Toby J. Blundell, Charles Agosta Mar 2023

Superconductivity And Fermi Surface Studies Of Β″-(Bedt-Ttf)2[(H2o)(Nh4)2cr(C2o4)3]·18-Crown-6, Brett Laramee, Raju Ghimire, David Graf, Lee Martin, Toby J. Blundell, Charles Agosta

Physics

We report rf-penetration depth measurements of the quasi-2D organic superconductor (Formula presented.) -(BEDT-TTF) (Formula presented.) [(H (Formula presented.) O)(NH (Formula presented.)) (Formula presented.) Cr(C (Formula presented.) O (Formula presented.)) (Formula presented.)]·18-crown-6, which has the largest separation between consecutive conduction layers of any 2D organic metal with a single packing motif. Using a contactless tunnel diode oscillator measurement technique, we show the zero-field cooling dependence and field sweeps up to 28 T oriented at various angles with respect to the crystal conduction planes. When oriented parallel to the layers, the upper critical field, (Formula presented.) T, which is the calculated paramagnetic …


Escape Dynamics Of Confined Undulating Worms, Animesh Biswas, Arshad Kudrolli Jan 2023

Escape Dynamics Of Confined Undulating Worms, Animesh Biswas, Arshad Kudrolli

Physics

We investigate the escape dynamics of oligochaeta Lumbriculus variegatus by confining them to a quasi-2D circular chamber with a narrow exit passage. The worms move by performing undulatory and peristaltic strokes and use their head to actively probe their surroundings. We show that the worms follow the chamber boundary with occasional reversals in direction and with velocities determined by the orientation angle of the body with respect to the boundary. The average time needed to reach the passage decreases with its width before approaching a constant, consistent with a boundary-following search strategy. We model the search dynamics as a persistent …


Dissolution-Driven Propulsion Of Floating Solids, Martin Chaigne, Michael Berhanu, Arshad Kudrolli Jan 2023

Dissolution-Driven Propulsion Of Floating Solids, Martin Chaigne, Michael Berhanu, Arshad Kudrolli

Physics

We show that unconstrained asymmetric dissolving solids floating in a fluid can move rectilinearly as a result of attached density currents which occur along their inclined surfaces. Solids in the form of boats composed of centimeter-scale sugar and salt slabs attached to a buoy are observed to move rapidly in water with speeds up to 5 mm/s determined by the inclination angle and orientation of the dissolving surfaces. While symmetric boats drift slowly, asymmetric boats are observed to accelerate rapidly along a line before reaching a terminal velocity when their drag matches the thrust generated by dissolution. By visualizing the …