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Related papers: Macroscopic Quantum Coherence in Molecular Magnets

200 papers

Double barrier heterostructures are model systems for the study of electron tunneling and discrete energy levels in a quantum well (QW). Until now resonant tunneling phenomena in metallicQW have been observed for limited thicknesses (1-2…

Mesoscale and Nanoscale Physics · Physics 2016-04-13 B. S. Tao , H. X. Yang , Y. L. Zuo , X. Devaux , G. Lengaigne , M. Hehn , D. Lacour , S. Andrieu , M. Chshiev , T. Hauet , F. Montaigne , S. Mangin , X. F. Han , Y. Lu

We show that the S/F/S Josephson $\varphi_0$-junction permits detection of macroscopic quantum tunneling and quantum oscillation of the magnetic moment by measuring the ac voltage across the junction. Exact expression for the tunnel…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 Eugene M. Chudnovsky

We make a theoretical study of the quantum oscillations of the tunneling magnetoresistance (TMR) as a function of the spacer layer thickness. Such oscillations were recently observed in tunneling junctions with a nonmagnetic metallic spacer…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 H. Itoh , J. Inoue A. Umerski , J. Mathon

Quantum interference phenomena in the conductivity of mesoscopic ferromagnets are considered, particularly with regard to the effects of geometric phases acquired by electrons propagating through regions of spatially varying magnetization…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Yuli Lyanda-Geller , I. L. Aleiner , Paul M. Goldbart

Transport and non-equilibrium magnetization in monolayers of magnetic molecules subject to a bias voltage are considered. We apply a master-equation approach going beyond the sequential-tunneling approximation to study the Coulomb-blockade…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Florian Elste , Carsten Timm

Macroscopic quantum coherence and spin-phase interference are studied between excited levels in single-domain ferromagnetic particles in a magnetic field along the hard anisotropy axis. The system has the general structure of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Pan Hui , Rong Lu , Jia-Lin Zhu , Yi Zhou

Manifestations of quantum coherence in the electronic conductance through nearly closed quantum dots in the Coulomb blockade regime are addressed. We show that quantum coherent tunneling processes explain some puzzling statistical features…

Mesoscale and Nanoscale Physics · Physics 2015-05-26 L. E. F. Foa Torres , C. H. Lewenkopf , H. M. Pastawski

Quantum tunneling of domain walls out of an impurity potential in a mesoscopic ferromagnetic sample is investigated. Using improved expressions for the domain wall mass and for the pinning potential, we find that the cross-over temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Hans-Benjamin Braun , Jordan Kyriakidis , Daniel Loss

We present an analytical theory on the heights of the quantum steps observed in the hysteresis loops of molecular magnets. By considering the dipolar interaction between molecular spins, our theory successfully yields the step heights…

Soft Condensed Matter · Physics 2009-11-07 Jie Liu , Biao Wu , Li-Bin Fu , Roberto B. Diener , Qian Niu

Coulomb blockade phenomena and quantum fluctuations are studied in mesoscopic metallic tunnel junctions with high charging energies. If the resistance of the barriers is large compared to the quantum resistance, transport can be described…

Condensed Matter · Physics 2009-10-22 Herbert Schoeller , Gerd Schoen

The tunneling splitting in biaxial ferrimagnetic particles at excited states with an explicit calculation of the prefactor of exponent is obtained in terms of periodic instantons which are responsible for tunneling at excited states and is…

Condensed Matter · Physics 2019-08-17 Yi-Hang Nie , Yan-Hong Jin , J. -Q Liang , F. -C Pu

We present a methodology based on quantum mechanics for assigning quantum conductivity when an ac field is applied across a variable gap between two plasmonic nanoparticles with an insulator sandwiched between them. The quantum tunneling…

We address quantum invisibility in the context of electronics in nanoscale quantum structures. We make use of the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with…

Mesoscale and Nanoscale Physics · Physics 2010-05-18 J. Fransson , H. C. Manoharan , A. V. Balatsky

We present detailed measurements of the discrete electron-tunneling level spectrum within nanometer-scale cobalt particles as a function of magnetic field and gate voltage, in this way probing individual quantum many-body eigenstates inside…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 M. M. Deshmukh , S. Gueron , E. Bonet , A. N. Pasupathy , S. Kleff , J. von Delft , D. C. Ralph

We study the phenomenon of macroscopic quantum tunneling (MQT) in small Josephson junctions (JJ) with an externally applied magnetic field. The latter results in the appearance of the Fraunhofer type modulation of the current density along…

Superconductivity · Physics 2009-11-13 Yu. N. Ovchinnikov , A. Barone , A. A. Varlamov

We propose a nonequilibrium Monte Carlo (MC) approach to explore nonequilibrium dynamical ferromagnetism of interacting single molecule magnets (SMMs). Both quantum spin tunneling and thermally activated spin reversal are successfully…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Gui-Bin Liu , Bang-Gui Liu

We calculate the response of a molecular magnet subject to a time-varying magnetic field and coupled to a heat bath. We propose that observations of calculated oscillations transverse to the field direction may be an effective way of…

Statistical Mechanics · Physics 2007-05-23 Maxime Clusel , Timothy Ziman

Prototype Josephson-junction based qubit coherence times are too short for quantum computing. Recent experiments probing superconducting phase qubits have revealed previously unseen fine splittings in the transition energy spectra. These…

We study the thermal transport in magnetic tunnel junctions. Thermal gradients across the tunneling barrier appear around the Fowler-Nordheim tunneling regime, due to the current-induced heat caused by quantum interference. Both…

Materials Science · Physics 2013-08-22 J. F. Feng , D. P. Liu , Q. L. Ma , H. X. Wei , X. F. Han

The spin relaxation in the molecular magnet \Mn12 is investigated by a novel type of high-frequency magnetic spectroscopy. By reversing the external magnetic field the intensities of the $|\pm 10>\to |\pm 9>$ transitions within the ground…

Strongly Correlated Electrons · Physics 2016-08-31 M. Dressel , B. Gorshunov , K. Rajagopal , S. Vongtragool , A. A. Mukhin