scholarly journals Monopole matter from magnetoelastic coupling in the Ising pyrochlore

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
D. Slobinsky ◽  
L. Pili ◽  
G. Baglietto ◽  
S. A. Grigera ◽  
R. A. Borzi
Keyword(s):  
Degrees Of Freedom ◽  
Ground States ◽  
Building Blocks ◽  
Ising Models ◽  
Magnetic Monopoles ◽  
Classical Approach ◽  
Spin Ice ◽  
Electric Moment ◽  
Pyrochlore Oxide ◽  
Ice Model

AbstractIsing models on a pyrochlore oxide lattice have become associated with spin ice materials and magnetic monopoles. Ever more often, effects connecting magnetic and elastic degrees of freedom are reported on these and other related frustrated materials. Here we extend a spin-ice Hamiltonian to include coupling between spins and the O−2 ions mediating superexchange; we call it the magnetoelastic spin ice model (MeSI). There has been a long search for a model in which monopoles would spontaneously become the building blocks of new ground-states: the MeSI Hamiltonian is such a model. In spite of its simplicity and classical approach, it describes the double-layered monopole crystal observed in Tb2Ti2O7. Additionally, the dipolar electric moment of single monopoles emerges as a probe for magnetism. As an example we show that some Coulomb phases could, in principle, be detected through pinch points associated with O−2-ion displacements.

Mechanically-Tunable Quantum Interference in Ferrocene-Based Single-Molecule Junctions

2020 ◽  
Author(s):  
María Camarasa-Gómez ◽  
Daniel Hernangómez-Pérez ◽  
Michael S. Inkpen ◽  
Giacomo Lovat ◽  
E-Dean Fung ◽  
...  
Keyword(s):  
Single Molecule ◽  
Quantum Interference ◽  
Degrees Of Freedom ◽  
Building Blocks ◽  
Ferrocene Derivative ◽  
Single Molecule Junctions ◽  
Molecule Junction ◽  
Single Molecule Junction ◽  
The Impact ◽  
D Orbitals

Ferrocenes are ubiquitous organometallic building blocks that comprise a Fe atom sandwiched between two cyclopentadienyl (Cp) rings that rotate freely at room temperature. Of widespread interest in fundamental studies and real-world applications, they have also attracted<br>some interest as functional elements of molecular-scale devices. Here we investigate the impact of<br>the configurational degrees of freedom of a ferrocene derivative on its single-molecule junction<br>conductance. Measurements indicate that the conductance of the ferrocene derivative, which is<br>suppressed by two orders of magnitude as compared to a fully conjugated analog, can be modulated<br>by altering the junction configuration. Ab initio transport calculations show that the low conductance is a consequence of destructive quantum interference effects that arise from the hybridization of metal-based d-orbitals and the ligand-based π-system. By rotating the Cp rings, the hybridization, and thus the quantum interference, can be mechanically controlled, resulting in a conductance modulation that is seen experimentally.<br>

scholarly journals Dimerization and oligomerization of DNA-assembled building blocks for controlled multi-motion in high-order architectures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ling Xin ◽  
Xiaoyang Duan ◽  
Na Liu
Keyword(s):  
Building Block ◽  
Degrees Of Freedom ◽  
Building Blocks ◽  
Single Type ◽  
Hierarchical Assembly ◽  
Optical Responses ◽  
Self Association ◽  
Living Organisms ◽  
Order Structures ◽  
Chiral System

AbstractIn living organisms, proteins are organized prevalently through a self-association mechanism to form dimers and oligomers, which often confer new functions at the intermolecular interfaces. Despite the progress on DNA-assembled artificial systems, endeavors have been largely paid to achieve monomeric nanostructures that mimic motor proteins for a single type of motion. Here, we demonstrate a DNA-assembled building block with rotary and walking modules, which can introduce new motion through dimerization and oligomerization. The building block is a chiral system, comprising two interacting gold nanorods to perform rotation and walking, respectively. Through dimerization, two building blocks can form a dimer to yield coordinated sliding. Further oligomerization leads to higher-order structures, containing alternating rotation and sliding dimer interfaces to impose structural twisting. Our hierarchical assembly scheme offers a design blueprint to construct DNA-assembled advanced architectures with high degrees of freedom to tailor the optical responses and regulate multi-motion on the nanoscale.

Systematic Synthesis and Applications of Novel Multi-Degree-of-Freedom Differential Systems

1992 ◽  
Author(s):  
Sridhar Kota ◽  
Srinivas Bidare
Keyword(s):  
Degrees Of Freedom ◽  
Building Blocks ◽  
Degree Of Freedom ◽  
Differential Systems ◽  
Practical Applications ◽  
Epicyclic Gear ◽  
Differential Mechanism ◽  
Long Time ◽  
Gear Trains ◽  
Drive Systems

Abstract A two-degree-of-freedom differential system has been known for a long time and is widely used in automotive drive systems. Although higher degree-of-freedom differential systems have been developed in the past based on the well-known standard differential, the number of degrees-of-freedom has been severely restricted to 2n. Using a standard differential mechanism and simple epicyclic gear trains as differential building blocks, we have developed novel whiffletree-like differential systems that can provide n-degrees of freedom, where n is any integer greater than two. Symbolic notation for representing these novel differentials is also presented. This paper presents a systematic method of deriving multi-degree-of-freedom differential systems, a three and four output differential systems and some of their practical applications.

scholarly journals Engineering the quantum-classical interface of solid-state qubits

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
David J Reilly
Keyword(s):  
Quantum Information ◽  
Solid State ◽  
Degrees Of Freedom ◽  
Technology Development ◽  
Fault Tolerant ◽  
Building Blocks ◽  
Experimental Physicist ◽  
And Mathematics ◽  
Classical Control ◽  
And Control

AbstractSpanning a range of hardware platforms, the building-blocks of quantum processors are today sufficiently advanced to begin work on scaling-up these systems into complex quantum machines. A key subsystem of all quantum machinery is the interface between the isolated qubits that encode quantum information and the classical control and readout technology needed to operate them. As few-qubit devices are combined to construct larger, fault-tolerant quantum systems in the near future, the quantum-classical interface will pose new challenges that increasingly require approaches from the engineering disciplines in combination with continued fundamental advances in physics, materials and mathematics. This review describes the subsystems comprising the quantum-classical interface from the viewpoint of an engineer, experimental physicist or student wanting to enter the field of solid-state quantum information technology. The fundamental signalling operations of readout and control are reviewed for a variety of qubit platforms, including spin systems, superconducting implementations and future devices based on topological degrees-of-freedom. New engineering opportunities for technology development at the boundary between qubits and their control hardware are identified, transversing electronics to cryogenics.

scholarly journals Magnetic monopoles in spin ice

Nature ◽  
2008 ◽  
Vol 451 (7174) ◽  
pp. 42-45 ◽  
Author(s):  
C. Castelnovo ◽  
R. Moessner ◽  
S. L. Sondhi
Keyword(s):  
Magnetic Monopoles ◽  
Spin Ice

scholarly journals Magnetic dipole configurations on honeycomb lattices: effect of finite size and boundaries

2012 ◽  
Vol 370 (1981) ◽  
pp. 5783-5793 ◽  
Author(s):  
Alexandra Schumann ◽  
Hartmut Zabel
Keyword(s):  
Magnetic Field ◽  
Boundary Conditions ◽  
Magnetic Dipole ◽  
Finite Size ◽  
Magnetic Monopoles ◽  
Spin Ice ◽  
Artificial Spin Ice

Artificial dipolar spin-ice patterns have attracted much attention recently because of their rich configurations and excitations in the form of Dirac strings connecting magnetic monopoles. We have analysed the distribution of excitations in the form of strings and vertices carrying magnetic charges Q =±3 q in honeycomb artificial spin-ice patterns. Two types of patterns are compared, those that terminate with open hexagons and those with closed hexagons. The dipole configurations and the frequency of spin-ice rule-violating Q =±3 q vertices depend slightly on the boundary conditions of the pattern. Upon rotation of the patterns by 2 π in a coercive magnetic field of 500 Oe, complete reversibility of the charge and string configuration is observed.

Cooperative Strategies and Genome Cybernetics in Formation of Complex Bacterial Patterns

1994 ◽  
Vol 367 ◽  
Author(s):  
Eshel Ben-Jacob ◽  
Ofer Shochet ◽  
Inon Cohen ◽  
Adam Tenenbaum ◽  
Andras CzirÓk ◽  
...  
Keyword(s):  
Pattern Formation ◽  
Degrees Of Freedom ◽  
Cooperative Behavior ◽  
Building Blocks ◽  
Growth Conditions ◽  
Living Systems ◽  
Cooperative Strategies ◽  
Additional Level ◽  
Bacterial Patterns ◽  
The Individual

AbstractWe present a study of interfacial pattern formation during growth of bacterial colonies. Growth of bacterial colonies bears similarities but presents an inherent additional level of complexity in comparison with non-living systems. In the former case, the building blocks themselves are living systems, each with its own autonomous self-interest and internal degrees of freedom. The bacteria have developed sophisticated communication channels, which they utilize when growth conditions are tough. Here we present a non-local communicating walkers model to study the effect of local bacterium-bacterium interaction and communication via chemotaxis signaling. We demonstrate how communication enables the colony to develop complex patterns in response to adverse growth conditions. This self-organization of the colony, which can be achieved only via cooperative behavior of the bacteria, may be viewed as the outcome of an interplay between the micro-level (the individual bacterium) and the macro-level (the colony). Some qualitative features of the complex morphologies can be accounted for by invoking ideas from pattern formation in non-living systems together with a simplified model of chemotactic “feedback”.

scholarly journals Out-of-equilibrium dynamics in the bidimensional spin-ice model

2012 ◽  
Vol 97 (3) ◽  
pp. 30002 ◽  
Author(s):  
D. Levis ◽  
L. F. Cugliandolo
Keyword(s):  
Spin Ice ◽  
Equilibrium Dynamics ◽  
Ice Model

scholarly journals “Color-Tripole Ice” as a Conceptual Generalization of “Spin Ice”

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Chia-Ren Hu
Keyword(s):  
High Energy Physics ◽  
Zero Point ◽  
High Energy ◽  
Magnetic Monopoles ◽  
Spin Ice ◽  
Elementary Excitations ◽  
Magnetic Dipoles ◽  
Frustrated Magnet ◽  
Statistical Mechanical ◽  
Energy Physics

“Spin Ice” is an exotic type of frustrated magnet realized in “pyrochlore” materials Ho2Ti2O7, Dy2Ti2O7, Ho2Sn2O7, and so forth, in which magnetic atoms (spins) reside on a sublattice made of the vertices of corner-sharing tetrahedra. Each spin is Ising-like with respect to a local axis which connects the centers of two tetrahedra sharing the vertex occupied by the spin. The macroscopically degenerate ground states of these magnets obey the “two-in two-out” “ice rule” within each tetrahedron. Magnetic monopoles and antimonopoles emerge as elementary excitations, “fractionalizing” the constituent magnetic dipoles. This system is also a novel type of statistical mechanical system. Here we introduce a conceptual generalization of “spin ice” to what we shall call “color-tripole ice,” in which three types of “color charges” can emerge as elementary excitations, which are Abelian approximations of the color charges introduced in high energy physics. Two two-dimensional (2D) models are introduced first, where the color charges are found to be 1D and constrained 2D, respectively. Generalizations of these two models to 3D are then briefly discussed. In the second one the color charges are likely 3D. Pauling-type estimates of the “residual (or zero-point) entropy” are also made for these models.

Sign in / Sign up

Export Citation Format

Share Document