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Related papers: Macroscopic Quantum Tunneling and the "cosmic" Jos…

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We have carried out systematic Macroscopic Quantum Tunneling (MQT) experiments on Nb/Al-AlO_x/Nb Josephson junctions (JJs) of different areas. Employing on-chip lumped element inductors, we have decoupled the JJs from their environmental…

Superconductivity · Physics 2010-11-19 Christoph Kaiser , Roland Schäfer , Michael Siegel

We analyze quantum-mechanical counterpart of Newtonian cosmology and show that effects of zero-point motion eliminate classical density singularity. Quantum effects are particularly significant for closed Universes where without the…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Eugene B. Kolomeisky

Macroscopic quantum tunneling (MQT) for a single fluxon moving along a long Josephson junction is studied theoretically. To introduce a fluxon-pinning force, we consider inhomogeneities made by modifying thickness of an insulating layer…

Condensed Matter · Physics 2009-10-28 Takeo Kato , Masatoshi Imada

Theoretical foundations of the problem of quantum spin tunneling in magnetic nanostructures are presented. Several model problems are considered in detail, including recent new results on tunneling in antiferromagnetic nanoparticles and…

Mesoscale and Nanoscale Physics · Physics 2008-02-03 Boris A. Ivanov , Alexei K. Kolezhuk

We investigate macroscopic quantum tunneling of a Bose condensate and how it is affected by the interatomic interaction. We study the dynamics of a condensate falling under gravity and scattering on a Gaussian potential barrier that models…

Statistical Mechanics · Physics 2009-11-07 L. Salasnich , A. Parola , L. Reatto

We investigate the effects of high-Q_c resonant cavity on macroscopic quantum tunneling (MQT) of fluxon both from a metastable state to continuum and from one degenerate ground-state of a double-well potential to the other. By using a set…

Superconductivity · Physics 2015-05-27 Ju H. Kim , Ramesh P. Dhungana

At total filling factor $\nu_T=1$, interlayer phase coherence in quantum Hall bilayers can result in a tunneling anomaly resembling the Josephson effect in the presence of strong fluctuations. The most robust experimental signature of this…

Mesoscale and Nanoscale Physics · Physics 2011-10-19 Timo Hyart , Bernd Rosenow

The Josephson effect is found to stem from the quantum behavior of massive photons existing in a superconducting medium. Accordingly, the Josephson coupling energy is found to be equal to the rest mass energy of these photons. The Josephson…

General Physics · Physics 2018-02-14 A. I. Arbab

The meaning of `tunneling' in a timeless theory such as quantum cosmology is discussed. A recent suggestion of `tunneling' of the macroscopic universe at the classical turning point is analyzed in an anisotropic and inhomogeneous toy model.…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Heinz-Dieter Conradi

Stochastic switching-current distribution in a graphene-based Josephson junction exhibits a crossover from the classical to quantum regime, revealing the macroscopic quantum tunneling (MQT) of a Josephson phase particle at low temperatures.…

Mesoscale and Nanoscale Physics · Physics 2012-11-15 Gil-Ho Lee , Dongchan Jeong , Jae-Hyun Choi , Yong-Joo Doh , Hu-Jong Lee

With microwave irradiation, the switching current of a Josephson junction coupled to a microscopic two-level system jumps randomly between two discrete states. We modeled the switching process of the coupled system with quantum jump…

Quantum Physics · Physics 2015-05-13 Xueda Wen , Yiwen Wang , Ning Dong , Guozhu Sun , Jian Chen , Lin Kang , Weiwei Xu , Peiheng Wu , Yang Yu

In the mixed state of layered superconductor the antiferromagnetic order of magnetic ions can create the spin-flop domains along the phase cores of the Josephson vortices. The paper discusses how this feature affects the macroscopic quantum…

Superconductivity · Physics 2012-10-01 Tomasz Krzyszton

We investigate macroscopic dynamical quantum tunneling (MDQT) in the driven Duffing oscillator, charateristic for Josephson junction physics and nanomechanics. Under resonant conditions between stable coexisting states of such systems we…

Superconductivity · Physics 2008-04-01 I. Serban , F. K. Wilhelm

We study the Josephson-like spin currents between two ferromagnetic metals by deriving the effective action of the junction. A DC spin Josephson current with the full O(3) symmetry is obtained. By the analogy to the superconducting…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Yu-Li Lee , Yu-Wen Lee

We present the quantum phase diagram of mesoscopic SQUID array. We predict different quan- tum phases and the phase boundaries along with several special points. We present the results of magnetic flux induced dissipation on these points…

Superconductivity · Physics 2011-08-24 Sujit Sarkar

In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hermann Grabert , Gert-Ludwig Ingold

We study macroscopic properties of a system of weakly interacting neutral bosons confined in a ring-shaped potential with a Josephson junction. We derive an effective low energy action for this system and evaluate its properties. In…

Quantum Gases · Physics 2010-06-15 Dmitry Solenov , Dmitry Mozyrsky

A textbook example of quantum mechanical effects is the coupling of two states through a tunnel barrier. In the case of macroscopic quantum states subject to interactions, the tunnel coupling gives rise to Josephson phenomena including Rabi…

Mesoscale and Nanoscale Physics · Physics 2014-06-13 M. Abbarchi , A. Amo , V. G. Sala , D. D. Solnyshkov , H. Flayac , L. Ferrier , I. Sagnes , E. Galopin , A. Lemaitre , G. Malpuech , J. Bloch

A key phenomenon related to the Josephson effect is oscillations of different properties of superconducting tunneling junctions with magnetic field. We consider magnetic oscillations of the critical current in stacks of intrinsic Josephson…

Superconductivity · Physics 2011-11-09 A. E. Koshelev

We analyze the influence of noise on magnetic properties of a su- perconducting loop which contains three Josephson junctions. This circuit is a classical analog of a persistent current (flux) qubit. A loop supercurrent induced by external…

Superconductivity · Physics 2009-11-13 E. Il'ichev , A. N. Omelyanchouk