Violation of the London Law and Onsager-Feynman quantization in multicomponent superconductors

Non-classical response to rotation is a hallmark of quantum ordered states such as superconductors and superfluids. The rotational responses of all currently known single-component "super" states of matter (superconductors, superfluids and supersolids) are largely described by two fundamental principles and fall into two categories according to whether the systems are composed of charged or neutral particles: the London law relating the angular velocity to a subsequently established magnetic field and the Onsager-Feynman quantization of superfluid velocity. These laws are theoretically shown to be violated in a two-component superconductor such as the projected liquid metallic states of hydrogen and deuterium at high pressures. The rotational responses of liquid metallic hydrogen or deuterium identify them as a new class of dissipationless states; they also directly point to a particular experimental route for verification of their existence.Comment: Nature Physics in print. This is an early version of the paper. The final version will be posted 6 months after its publication Nature Physics, according to the journal polic

Length scales, collective modes, and type-1.5 regimes in three-band superconductors

The recent discovery of iron pnictide superconductors has resulted in a rapidly growing interest in multiband models with more than two bands. In this work we specifically focus on the properties of three-band Ginzburg-Landau models which do not have direct counterparts in more studied two-band models. First we derive normal modes and characteristic length scales in the conventional U(1) three-band Ginzburg-Landau model as well as in its time reversal symmetry broken counterpart with $U(1)\times Z_2$ symmetry. We show that in the latter case, the normal modes are mixed phase/density collective excitations. A possibility of the appearance of a massless phase-difference mode associated with fluctuations of the phase difference is also discussed. Next we show that gradients of densities and phase differences can be inextricably intertwined in vortex excitations in three-band models. This can lead to very long-range attractive intervortex interactions and appearance of type-1.5 regimes even when the intercomponent Josephson coupling is large. In some cases it also results in the formation of a domain-like structures in the form of a ring of suppressed density around a vortex across which one of the phases shifts by $\pi$. We also show that field-induced vortices can lead to a change of broken symmetry from U(1) to $U(1)\times Z_2$ in the system. In the type-1.5 regime, it results in a semi-Meissner state where the system has a macroscopic phase separation in domains with broken U(1) and $U(1)\times Z_2$ symmetries.Comment: Version 3: Corrected som inconstancies in the parameter set in Fig.2 Also som minor typos corrected. No changes to results or conclusion

Angular distributions of bent-crystal deflected protons

Penetration of relativistic protons into bent crystals at small angles with respect to the bent crystallographic planes has been evaluated within continuous potential approximation. Namely, in this paper the numerical solution of the equation of motion for channeled and quasi-channeled relativistic protons is presented. Proton trajectories under the conditions of both channeling and volume reflection were simulated. The angular distributions of outgoing beam protons are calculated with the parameters of recent CERN experiments. The rather good agreement with experimental data is achieved

Dual neutral variables and knot solitons in triplet superconductors

In this paper we derive a dual presentation of free energy functional for spin-triplet superconductors in terms of gauge-invariant variables. The resulting equivalent model in ferromagnetic phase has a form of a version of the Faddeev model. This allows one in particular to conclude that spin-triplet superconductors allow formation of stable finite-length closed vortices (the knotted solitons).Comment: Replaced with version published in PRL (added a discussion of the effect of the coupling of the fields {\vec s} and {\vec C} on knot stability). Latest updates of the paper and miscellaneous links related to knotted solitons are also available at the homepage of the author http://www.teorfys.uu.se/PEOPLE/egor/ . Animations of knotted solitons by Hietarinta and Salo are available at http://users.utu.fi/h/hietarin/knots/c45_p2.mp

The Quark Gluon Pion Plasma

While it is commonly believed that there is a {\it direct} transition from the hadronic to a quark gluon phase at high temperature, it would be prejudicial to rule out a sequence of dynamically generated intermediate scales. Using as guide, an effective lagrangian with unconfined gluons and constituent quarks, interacting with a chiral multiplet, we examine a scenario in which the system undergoes first-order transitions at $T_{comp}$, the compositeness scale of the pions, at $T_{\chi}$, the scale for spontaneous chiral symmetry breaking, and at $T_c$, the confinement temperature. We find that at current energies, it is likely that the formation temperature of the plasma, $T_0 < T_{comp}$, and that this is therefore a quark gluon pion plasma (QGPP) rather than the usual quark gluon plasma (QGP). We propose some dilepton-related signatures of this scenario.Comment: Rewritten, new figure