@article{1133,
abstract = {It is a common knowledge that an effective interaction of a quantum impurity with an electromagnetic field can be screened by surrounding charge carriers, whether mobile or static. Here we demonstrate that very strong, "anomalous" screening can take place in the presence of a neutral, weakly polarizable environment, due to an exchange of orbital angular momentum between the impurity and the bath. Furthermore, we show that it is possible to generalize all phenomena related to isolated impurities in an external field to the case when a many-body environment is present, by casting the problem in terms of the angulon quasiparticle. As a result, the relevant observables such as the effective Rabi frequency, geometric phase, and impurity spatial alignment are straightforward to evaluate in terms of a single parameter: the angular-momentum-dependent screening factor.},
author = {Yakaboylu, Enderalp and Lemeshko, Mikhail},
issn = {00319007},
journal = {Physical Review Letters},
number = {8},
publisher = {American Physical Society},
title = {{Anomalous screening of quantum impurities by a neutral environment}},
doi = {10.1103/PhysRevLett.118.085302},
volume = {118},
year = {2017},
}
@article{1162,
abstract = {Selected universal experimental properties of high-temperature superconducting (HTS) cuprates have been singled out in the last decade. One of the pivotal challenges in this field is the designation of a consistent interpretation framework within which we can describe quantitatively the universal features of those systems. Here we analyze in a detailed manner the principal experimental data and compare them quantitatively with the approach based on a single-band model of strongly correlated electrons supplemented with strong antiferromagnetic (super)exchange interaction (the so-called t−J−U model). The model rationale is provided by estimating its microscopic parameters on the basis of the three-band approach for the Cu-O plane. We use our original full Gutzwiller wave-function solution by going beyond the renormalized mean-field theory (RMFT) in a systematic manner. Our approach reproduces very well the observed hole doping (δ) dependence of the kinetic-energy gain in the superconducting phase, one of the principal non-Bardeen-Cooper-Schrieffer features of the cuprates. The calculated Fermi velocity in the nodal direction is practically δ-independent and its universal value agrees very well with that determined experimentally. Also, a weak doping dependence of the Fermi wave vector leads to an almost constant value of the effective mass in a pure superconducting phase which is both observed in experiment and reproduced within our approach. An assessment of the currently used models (t−J, Hubbard) is carried out and the results of the canonical RMFT as a zeroth-order solution are provided for comparison to illustrate the necessity of the introduced higher-order contributions.},
author = {Spałek, Jozef and Zegrodnik, Michał and Kaczmarczyk, Jan},
issn = {24699950},
journal = {Physical Review B - Condensed Matter and Materials Physics},
number = {2},
publisher = {American Physical Society},
title = {{Universal properties of high temperature superconductors from real space pairing t-J-U model and its quantitative comparison with experiment}},
doi = {10.1103/PhysRevB.95.024506},
volume = {95},
year = {2017},
}
@article{1163,
abstract = {We investigate the effect of the electron-hole (e-h) symmetry breaking on d-wave superconductivity induced by non-local effects of correlations in the generalized Hubbard model. The symmetry breaking is introduced in a two-fold manner: by the next-to-nearest neighbor hopping of electrons and by the charge-bond interaction - the off-diagonal term of the Coulomb potential. Both terms lead to a pronounced asymmetry of the superconducting order parameter. The next-to-nearest neighbor hopping enhances superconductivity for h-doping, while diminishes it for e-doping. The charge-bond interaction alone leads to the opposite effect and, additionally, to the kinetic-energy gain upon condensation in the underdoped regime. With both terms included, with similar amplitudes, the height of the superconducting dome and the critical doping remain in favor of h-doping. The influence of the charge-bond interaction on deviations from symmetry of the shape of the gap at the Fermi surface in the momentum space is briefly discussed.},
author = {Wysokiński, Marcin and Kaczmarczyk, Jan},
issn = {09538984},
journal = {Journal of Physics: Condensed Matter},
number = {8},
publisher = {IOP Publishing Ltd.},
title = {{Unconventional superconductivity in generalized Hubbard model role of electron–hole symmetry breaking terms}},
doi = {10.1088/1361-648X/aa532f},
volume = {29},
year = {2017},
}
@article{1204,
abstract = {In science, as in life, "surprises" can be adequately appreciated only in the presence of a null model, what we expect a priori. In physics, theories sometimes express the values of dimensionless physical constants as combinations of mathematical constants like π or e. The inverse problem also arises, whereby the measured value of a physical constant admits a "surprisingly" simple approximation in terms of well-known mathematical constants. Can we estimate the probability for this to be a mere coincidence, rather than an inkling of some theory? We answer the question in the most naive form.},
author = {Amir, Ariel and Lemeshko, Mikhail and Tokieda, Tadashi},
journal = {American Mathematical Monthly},
number = {6},
pages = {609 -- 612},
publisher = {Mathematical Association of America},
title = {{Surprises in numerical expressions of physical constants}},
doi = {10.4169/amer.math.monthly.123.6.609},
volume = {123},
year = {2016},
}
@article{1206,
abstract = {We study a polar molecule immersed in a superfluid environment, such as a helium nanodroplet or a Bose–Einstein condensate, in the presence of a strong electrostatic field. We show that coupling of the molecular pendular motion, induced by the field, to the fluctuating bath leads to formation of pendulons—spherical harmonic librators dressed by a field of many-particle excitations. We study the behavior of the pendulon in a broad range of molecule–bath and molecule–field interaction strengths, and reveal that its spectrum features a series of instabilities which are absent in the field-free case of the angulon quasiparticle. Furthermore, we show that an external field allows to fine-tune the positions of these instabilities in the molecular rotational spectrum. This opens the door to detailed experimental studies of redistribution of orbital angular momentum in many-particle systems. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim},
author = {Redchenko, Elena and Lemeshko, Mikhail},
journal = {ChemPhysChem},
number = {22},
pages = {3649 -- 3654},
publisher = {Wiley-Blackwell},
title = {{Libration of strongly oriented polar molecules inside a superfluid}},
doi = {10.1002/cphc.201601042},
volume = {17},
year = {2016},
}