Results 71 to 80 of about 293,764 (287)

On the use of projectors for Hamiltonian systems and their relationship with Dirac brackets

, 2012
The role of projectors associated with Poisson brackets of constrained Hamiltonian systems is analyzed. Projectors act in two instances in a bracket: in the explicit dependence on the variables and in the computation of the functional derivatives.
A Back, C Chandre, E Tassi, Hanson A, L de Guillebon, Marsden J E, P J Morrison, Zakharov V E   +7 more
core   +4 more sources

Self‐Cooling Molecular Spin Qudits

Advanced Materials, EarlyView.
A material made of [GdEr] molecular dimers can encode a qudit and perform as a magnetic refrigerant. Microwave resonant pulses coherently manipulate its 16 spin states, while direct demagnetization measurements cool the material and a device down to temperatures below 1 K.
Elías Palacios, David Aguilà, David Gracia, Diamatoula Maniaki, Leoní A. Barrios, Alessandro Chiesa, Jesús I. Martínez, Valentin Novikov, Olivier Roubeau, Stefano Carretta, Marco Evangelisti, Guillem Aromí, Fernando Luis   +12 more
wiley   +1 more source

Hot spots along the Fermi contour of high-T c cuprates analyzed by s-d exchange interaction

SN Applied Sciences, 2022
Article Highlights Strong anisotropy of the scattering rate along the Fermi surface is explained as a consequence of s-d Kondo interaction. The linear temperature dependence of the Ohmic resistance is caused by wave scattering by thermal density ...
Todor M. Mishonov, Nedelcho I. Zahariev, Hassan Chamati, Albert M. Varonov   +3 more
doaj   +1 more source

Polyimide‐Linked Hexaazatriphenylene‐Based Porous Organic Polymer with Multiple Redox‐Active Sites as a High‐Capacity Organic Cathode for Lithium‐Ion Batteries

Advanced Materials, EarlyView.
A high‐capacity polyimide‐linked porous organic polymer (HAT‐PTO) incorporating numerous redox‐active centers is synthesized via a hydrothermal reaction, delivering a high theoretical capacity of 484 mAh g−1. In situ hybridization with carboxyl‐functionalized multiwalled carbon nanotubes enhances conductivity and stability, achieving 397 mAh g−1 at C ...
Arindam Mal, Jonathan Caroni, Asia Patriarchi, Olivera Luzanin, Rafael Ramos, Jan Bitenc, Manuel Melle‐Franco, Manuel Souto   +7 more
wiley   +1 more source

Simple and High-Precision Hamiltonian Simulation by Compensating Trotter Error with Linear Combination of Unitary Operations

PRX Quantum
Trotter and linear combination of unitary (LCU) operations are two popular Hamiltonian simulation methods. The Trotter method is easy to implement and enjoys good system-size dependence endowed by commutator scaling, while the LCU method admits high ...
Pei Zeng, Jinzhao Sun, Liang Jiang, Qi Zhao   +3 more
doaj   +1 more source

Homoclinic Orbits for Asymptotically Linear Hamiltonian Systems

Journal of Functional Analysis, 2001
The existence of a homoclinic orbit is proved in the paper for a Hamiltonian system \[ \dot z=JH_z(z,t),\tag{1} \] where \(z=(p,q)\in \mathbb R^{2N}\) and \(J=\left (\begin{smallmatrix} 0 & -I\\ I & 0\end{smallmatrix} \right)\). Furthermore, \(H(z,t)=\frac{1}{2}Az\cdot z+G(z,t)\) and \(H(0,t)=0\) with \(G_z(z,t)/|z|\to 0\) uniformly in \(t\) as \(z\to ...
Szulkin, Andrzej, Zou, Wenming
openaire   +2 more sources

High Charge Carrier Mobility in Non‐Conjugated 3D Covalent Organic Frameworks

Advanced Materials, EarlyView.
A non‐conjugated 3D COF constructed via boronate ester linkages from tetraphenylene and pyrene‐based monomers is reported, which exhibits a high charge carrier mobility of 14 ± 1 cm2 V−1 s−1. ABSTRACT π‐Conjugation, π–π stacking, and long‐range order play a central role in determining charge transport efficiency in organic materials.
Joaquín Almarza, Karol Strutyński, Shuai Fu, Yifan Chen, Natalia M. Padial, Isabel del Barrio Gómez, Carlos Martí‐Gastaldo, Andrei N. Khlobystov, Mischa Bonn, Hai I. Wang, Manuel Melle‐Franco, Aurelio Mateo‐Alonso   +11 more
wiley   +1 more source

Quantum transport in chains with noisy off-diagonal couplings

, 2005
We present a model for conductivity and energy diffusion in a linear chain described by a quadratic Hamiltonian with Gaussian noise. We show that when the correlation matrix is diagonal, the noise-averaged Liouville-von Neumann equation governing the ...
Andrey Pereverzev, Eric R. Bittner, Fermi E., Haug H., Ovchinnikov A.   +4 more
core   +1 more source

When Poor Exciton Dissociation Limits Photocurrents in Organic Solar Cells: Why Low Offset Non‐Fullerene Acceptor Blends Can't Be Efficient

Advanced Materials, EarlyView.
The energetic offset between the donor and the acceptor components in organic photoactive layers is central to the tradeoff between photovoltage and photocurrent losses. This Perspective covers the most important issues surrounding this topic in non‐fullerene acceptor blends, from the difficulty of accurately determining state energies and driving ...
Dieter Neher, Manasi Pranav
wiley   +1 more source

Deformation quantization of linear dissipative systems

, 2005
A simple pseudo-Hamiltonian formulation is proposed for the linear inhomogeneous systems of ODEs. In contrast to the usual Hamiltonian mechanics, our approach is based on the use of non-stationary Poisson brackets, i.e.
A A Sharapov, Arnold V I, Blasone M Jizba P, Devaney R L, Dito G, Dodonov V V, Douglas J, Fedosov B V, Gitman D M, Kanai E, Kazinski P O, Kupriyanov V G Lyakhovich S L Sharapov A A Aminova A V, Landau L D, Lopez G Lopez X Gonzalez G, Mensky M B, Messer J, Perelomov A M, Rosenau M Caldeira A Dutra S Westfahl H, S L Lyakhovich, V G Kupriyanov, Weber J, Woodhouse N J M   +21 more
core   +3 more sources