DSpace Community:
https://dspace.lboro.ac.uk/2134/92
20160207T13:22:40Z

Effect of ordered array of magnetic dots on the dynamics of Josephson vortices in stacked SNS Josephson junctions under DC and AC current
https://dspace.lboro.ac.uk/2134/20100
Title: Effect of ordered array of magnetic dots on the dynamics of Josephson vortices in stacked SNS Josephson junctions under DC and AC current
Authors: Berdiyorov, G.R.; Savel'ev, Sergey; Kusmartsev, F.V.; Peeters, F.M.
Abstract: We use the anisotropic timedependent GinzburgLandau theory to investigate the effect of a square array of outofplane magnetic dots on the dynamics of Josephson vortices (fluxons) in artificial stacks of superconductingnormalsuperconducting (SNS) Josephson junctions in the presence of external DC and AC currents. Periodic pinning due to the magnetic dots distorts the triangular lattice of fluxons and results in the appearance of commensurability features in the currentvoltage characteristics of the system. For the larger values of the magnetization, additional peaks appear in the voltagetime characteristics of the system due to the creation and annihilation of vortexantivortex pairs. Peculiar changes in the response of the system to the applied current is found resulting in a “superradiant” vortexflow state at large current values, where a rectangular lattice of moving vortices is formed. Synchronizing the motion of fluxons by adding a small ac component to the biasing dc current is realized. However, we found that synchronization becomes difficult for large magnetization of the dots due to the formation of vortexantivortex pairs.
Description: This is an open access article distributed
under the terms of the Creative Commons Attribution
License (http://creativecommons.org/licenses/by/4.0), which
permits unrestricted use, distribution, and reproduction in any
medium, provided the original work is properly cited.
20150101T00:00:00Z

Establishing a wellbeing equilibrium for science trainee teachers
https://dspace.lboro.ac.uk/2134/20020
Title: Establishing a wellbeing equilibrium for science trainee teachers
Authors: Turner, Sarah; Braine, Maggie; Walsh, Michael
Abstract: For trainee teachers, juggling “worklife balance” can be overwhelmingly impossible. A 90 minute lecture was trialled with a cohort of PGCE Science trainee teachers containing models and theories to support teacher wellbeing and enhance understanding of difficult pupil behaviour. Findings revealed that a lecture style of wellbeing input was extremely positive and that the therapeutic models were highly regarded. This type of intervention was reported necessary to support trainee teachers and equip them for their career.
Description: This article was published in the journal Science Teacher Education [© Association for Science Education].
20150101T00:00:00Z

Snake states and their symmetries in graphene
https://dspace.lboro.ac.uk/2134/19995
Title: Snake states and their symmetries in graphene
Authors: Liu, Yang; Tiwari, Rakesh P.; Brada, Matej; Bruder, C.; Kusmartsev, F.V.; Mele, Elisa
Abstract: Snake states are open trajectories for charged particles propagating in two dimensions under the influence of a
spatially varying perpendicular magnetic field. In the quantum limit they are protected edge modes that separate
topologically inequivalent ground states and can also occur when the particle density rather than the field is made
nonuniform. We examine the correspondence of snake trajectories in singlelayer graphene in the quantum limit
for two families of domain walls: (a) a uniform doped carrier density in an antisymmetric field profile and (b)
antisymmetric carrier distribution in a uniform field. These families support different internal symmetries but the
same pattern of boundary and interface currents. We demonstrate that these physically different situations are
gauge equivalent when rewritten in a Nambu doubled formulation of the two limiting problems. Using gauge
transformations in particlehole space to connect these problems, we map the protected interfacial modes to
the Bogoliubov quasiparticles of an interfacial onedimensional pwave paired state. A variational model is
introduced to interpret the interfacial solutions of both domain wall problems.
20150101T00:00:00Z

Modeling an adiabatic quantum computer via an exact map to a gas of particles
https://dspace.lboro.ac.uk/2134/19903
Title: Modeling an adiabatic quantum computer via an exact map to a gas of particles
Authors: Zagoskin, Alexandre M.; Savel'ev, Sergey; Nori, Franco
Abstract: We map adiabatic quantum evolution on the classical Hamiltonian dynamics of a 1D gas (Pechukas gas) and simulate the latter numerically. This approach turns out to be both insightful and numerically efficient, as seen from our example of a CNOT gate simulation. For a general class of Hamiltonians we show that the escape probability from the initial state scales no faster than \dot{\lambda}^{\gamma}, where \dot{\lambda} is the adiabaticity parameter. The scaling exponent for the escape probability is \gamma = 1/2 for all levels, except the edge (bottom and top) ones, where \gamma <~1/3. In principle, our method can solve arbitrarily large adiabatic quantum Hamiltonians.
Description: This article was published in the journal, Physical Review Letters [© American Physical Society] and the definitive version is available at: http://dx.doi.org/10.1103/PhysRevLett.98.120503
20070101T00:00:00Z