On the supersymmetric partition function in QCD-inspired random matrix models

We show that the expression for the supersymmetric partition function of the chiral unitary (Laguerre) ensemble conjectured recently by Splittorff and Verbaarschot [Phys. Rev. Lett. 90, 041601 (2003)] follows from the general expression derived recently by Fyodorov and Strahov [J. Phys. A: Math. Gen. 36, 3203 (2003)].     

The Amigó paradigm of forbidden/missing patterns: a detailed analysis

We deal here with the issue of determinism versus randomness in time series (TS), withthe goal of identifying their relative importance in a given TS. To this end we extend (i)the use of ordinal patterns based probability distribution functions associated to a TS[C. Bandt and B. Pompe, Phys. Rev. Lett. 88, 174102 (2002)] and (ii) theso-called Amigó paradigm of forbidden/missing patterns [J.M. Amigó et al., Europhys. Lett.79, 50001 (2007)], to analyze deterministic finite TS contaminated withstrong additive noises of different correlation-degree. Useful information on thedeterministic component of the original time series is obtained with the help of theso-called causal entropy-complexity plane [O.A. Rosso et al., Phys. Rev. Lett.99, 154102 (2007)].     

The smallest absorption refrigerator: the thermodynamics of a system with quantum local detailed balance

We study the thermodynamics of a quantum system interacting with different baths in the repeated interaction framework. In an appropriate limit, the evolution takes the Lindblad form and the corresponding thermodynamic quantities are determined by the state of the full system plus baths. We identify conditions under which the thermodynamics of the open system can be described only by system properties and find a quantum local detailed balance condition with respect to an equilibrium state that may not be a Gibbs state. The three-qubit refrigerator introduced in Linden et al. [Phys. Rev. Lett. 105, 130401 (2010)] and Skrzypczyk et al. [J. Phys. A: Math. Theory 44, 492002 (2011)] is an example of such a system. From a repeated interaction microscopic model we derive the Lindblad equation that describes its dynamics and discuss its thermodynamic properties for arbitrary values of the internal coupling between the qubits. We find that external power (proportional to the internal coupling strength) is required to bring the system to its steady state, but once there, it works autonomously as discussed in Linden et al. [Phys. Rev. Lett. 105, 130401 (2010)] and Skrzypczyk et al. [J. Phys. A: Math. Theory 44, 492002 (2011)].     

Topological Hall Effect of Spin-2 Condensate in a Time and Space-Dependent Magnetic Field

We simulate the dynamics of spin-2 ⁸⁷Rb condensate in a time and space-dependent magnetic field with a time-dependent variational approach. The topological Hall effect is observed, which has been realized in the experiment of spin-1 ²³Na condensate [Phys. Rev. Lett. 111, 245301 (2013)]. A driving-induced resonance behavior is observed.     

Inhomogeneous Heisenberg spin chain and quantum vortex filament as non-holonomically deformed NLS systems

Through the Hasimoto map, various dynamical systems can be mapped to different integrodifferential generalizations of Nonlinear Schrödinger (NLS) family of equations some of which are known to be integrable. Two such continuum limits, corresponding to the inhomogeneous XXX Heisenberg spin chain [J. Phys. C 15, L1305 (1982)] and that of a thin vortex filament moving in a superfluid with drag [Eur. Phys. J. B 86, 275 (2013) 86; Phys. Rev. E 91, 053201 (2015)], are shown to be particular non-holonomic deformations (NHDs) of the standard NLS system involving generalized parameterizations. Crucially, such NHDs of the NLS system are restricted to specific spectral orders that exactly complements NHDs of the original physical systems. The specific non-holonomic constraints associated with these integrodifferential generalizations additionally posses distinct semi-classical signature.     

First-principles simulations for attosecond photoelectron spectroscopy based on time-dependent density functional theory

We develop a first-principles simulation method for attosecond time-resolved photoelectron spectroscopy. This method enables us to directly simulate the whole experimental processes, including excitation, emission and detection on equal footing. To examine the performance of the method, we use it to compute the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) experiments of gas-phase Argon. The computed RABBITT photoionization delay is in very good agreement with recent experimental results from [Klünder et al., Phys. Rev. Lett. 106, 143002 (2011)] and [Guénot et al., Phys. Rev. A 85, 053424 (2012)]. This indicates the significance of a fully-consistent theoretical treatment of the whole measurement process to properly describe experimental observables in attosecond photoelectron spectroscopy. The present framework opens the path to unravel the microscopic processes underlying RABBITT spectra in more complex materials and nanostructures.     

Method for calculating photoionization cross sections of fullerenes in the local density and random phase approximations

A method for calculating the photoionization cross sections of fullerenes taking into account many-electron correlations on the basis of the local density and random phase approximations is proposed and implemented. Calculations are made specifically for fullerenes C₆₀ and C₂₀. It is shown that the photoionization spectrum of C₆₀ acquires a plasmon resonance whose position and magnitude are in good agreement with experimental results [I.V. Hertel, H. Steger, J. de Vries et al., Phys. Rev. Lett. 68, 784 (1992)] and with the results of other calculations [M.J. Puska and R.N. Nieminen, Phys. Rev. A47, 1181 (1993)]. The emergence of a giant resonance is predicted in the photoionization spectrum of fullerene C₂₀ with the center at a photon energy on the order of 27 eV, which corresponds to the frequency of resonant surface plasmon oscillations in a conducting sphere.     

Quantum limits of feedback cooling in optical lattices

A quantum-mechanical analysis of feedback cooling [see Phys. Rev. Lett. 94, 153002 (2005)] of atoms trapped in a far-off-resonant optical lattice is presented. The model considered is valid for ultralow energies of atoms, thus, allowing for the study of an ultimate cooling limit. The influence of the measurement-induced noise and feedback-induced atom-atom correlations on the cooling efficiency is discussed. It is shown that there are regimes where the quantum noise can be effectively compensated for.     

Magnetic geodynamics

Several decades since the work E. P. Velikhov, Zh. Éksp. Teor. Fiz. 36, 1398 (1959) [Sov. Phys. JETP 9, 995 (1959)] [1] concerning magnetorotational instability was published, great astrophysical interest has been manifested in the mechanism of generating a magnetic field in a rotating well-conducting medium in view of difficulties in the development of the theory of anomalous matter transfer in accretion discs both upon the formation of stars and planets from gaseous conglomerations and upon the formation of a galactic core with a black hole at the center { S. A. Balbus and J. F. Hawley, Astrophys. J. 376, 214 (1991) [2] and G. Ruediger and R. Hollerbach, The Magnetic Universe (Wiley-VCH, Weinheim, 2004) [3]}. Attempts to experimentally observe the magnetorotational instability were successful only for spherical geometry in experiments initially devoted to the verification of geomagnetic dynamo theory {D. R. Sisan et al., Phys. Rev. Lett. 93, 114502 (2004) [4]}. In experiments with liquid sodium in the complete absence of temperature gradients and, therefore, convection, which is very important for the conventional theory of the geomagnetic dynamo, the generation of the magnetic field was obtained due to the development of the magnetorotational instability, which is usually ignored when developing the theory of the origin of the Earth’s magnetic field. The results obtained in this work enable one to develop a theory of geomagnetic dynamo that is primarily based on the magnetorotational instability, which provides a new insight into not only the origin of the Earth’s magnetic field but its evolution in time.     

Discrete breathers in alpha-uranium

Uranium is an important radioactive material used in the field of nuclear energy and it is interesting from the scientific point of view because it possesses unique structure and properties. There exist several experimental reports on anomalies of physical properties of uranium that have not been yet explained. Manley et al. [Phys. Rev. Lett. 96, 125501 (2006); Phys. Rev. B 77, 214305 (2008)] speculate that the excitation of discrete breathers (DBs) could be the reason for anisotropy of thermal expansion and for the deviation of heat capacity from the theoretical prediction in the high temperature range. In the present work, with the use of molecular dynamics, the existence of DBs in α-uranium is demonstrated and their properties are studied. It is found that DB frequency lies above the phonon band and increases with DB amplitude. DB is localized on half a dozen of atoms belonging to a straight atomic chain. DB in uranium, unlike DBs in fcc, bcc and hcp metals, is almost immobile. Thus, the DB reported in this study cannot contribute to thermal conductivity and the search for other types of DBs in α-uranium should be continued. Our results demonstrate that even metals with low-symmetry crystal lattices such as the orthorhombic lattice of α-uranium can support DBs.     

Positions of the magnetoroton minima in the fractional quantum Hall effect

The multitude of excitations of the fractional quantum Hall state are very accurately understood, microscopically, as excitations of composite fermions across their Landau-like Λ levels. In particular, the dispersion of the composite fermion exciton, which is the lowest energy spin conserving neutral excitation, displays filling-factor-specific minima called “magnetoroton” minima. Simon and Halperin employed the Chern-Simons field theory of composite fermions [Phys. Rev. B 48, 17368 (1993)] to predict the magnetoroton minima positions. Recently, Golkar et al. [Phys. Rev. Lett. 117, 216403 (2016)] have modeled the neutral excitations as deformations of the composite fermion Fermi sea, which results in a prediction for the positions of the magnetoroton minima. Using methods of the microscopic composite fermion theory we calculate the positions of the roton minima for filling factors up to 5/11 along the sequence s/ (2s + 1) and find them to be in reasonably good agreement with both the Chern-Simons field theory of composite fermions and Golkar et al.’s theory. We also find that the positions of the roton minima are insensitive to the microscopic interaction in agreement with Golkar et al.’s theory. As a byproduct of our calculations, we obtain the charge and neutral gaps for the fully spin polarized states along the sequence s/ (2s ± 1) in the lowest Landau level and the n = 1 Landau level of graphene.     

Semi-Quantum Private Comparison Using Single Photons

Recently, by using the BB84 quantum key distribution (QKD) protocol, Sun et al. put forward two quantum private comparison (QPC) protocols with a semi-honest third party (TP) and a malicious TP, respectively (Sun et al., Quantum Inf. Process. 14, 2125–2133, 2015). In this paper, we absorb the concept of semi-quantumness suggested by Boyer et al. (Phys. Rev. Lett. 99(14), 140501, 2007 and Phys. Rev. A 79(3), 032341, 2009) into Sun et al.’s QPC protocols and construct two corresponding SQPC protocols. The common interesting feature of the proposed SQPC protocols is that apart from the establishment of shared keys between different participants, the rest parts of the protocols are completely classical. The output correctness and the security of the proposed SQPC protocols are validated. Compared with the present SQPC protocols, the advantages of the proposed SQPC protocols lies in the following aspects: on the aspect of quantum resource, they employ single photons rather than Bell entangled states; with respect to quantum measurement for TP, they need single-photon measurements rather than Bell state measurements; as for quantum entanglement swapping, they do not need it at all; and the second proposed SQPC protocol takes effect under a malicious TP and makes TP know neither the genuine contents of secret inputs nor the comparison result.     

Laser fields at flat interfaces: II. Plasmon resonances in aluminium photoelectron spectra

Using the model derived in paper I?[G. Ra?eev, Eur. Phys. J. D 66, 167 (2012)], this work presents calculations of the photoelectron spectrum (PES) of low index aluminium surfaces in the 10?C30?eV region. The laser is p or transverse magnetic linearly polarized incident on a flat structureless surface and its fields are modeled in I using the vector potential in the temporal gauge. This model uses a tensor and non-local isotropic (TNLI) susceptibility and solves the classical Ampère-Maxwell equation through the use of the vector potential from the electron density-coupled integro-differential equations (VPED-CIDE). The PE cross sections are the squares of the PE transition moments calculated using the VPED-CIDE vector potential function of the penetration coordinate. The PES is obtained in a one step model using either the Fermi golden rule or the Weisskopf-Wigner (WW) expressions. The WW cross section PES compares favorably with the experimental angle and energy resolved photoelectron yield (AERPY) spectrum of Levinson et?al. [Phys. Rev. Lett. 43, 952 (1979)], Levinson and Plummer [Phys. Rev. B 24, 628 (1981)] for Al(001) and of Barman et?al.?[Phys. Rev. B 58, R4285 (1998)], Barman [Curr. Sci. 88, 54 (2005)] for Al(111) surfaces. As in the experiment, our theoretical AERPY displays the multipole surface plasmon resonance at 11.32/12.75 eV for Al(001)/Al(111), mainly due to the surface contribution |??? _f |p·A|?? _i ?|², the bulk plasmon minimum at 15 eV and the two single particle excitation resonances at about 16 and 22 eV. The nature of the plasmon resonances of the PES is analyzed using the reflectance, the electron density induced by the laser and Feibelman??s parameter d _?? all introduced in paper?I.     

Vision of nuclear physics with photo-nuclear reactions by laser-driven $\sf \gamma$ beams

A laser-accelerated dense electron sheet with an energy \(E=\tilde{\gamma} mc^2\) can be used as a relativistic mirror to coherently reflect a second laser with photon energy ?ω, thus generating by the Doppler boost [A. Einstein, Annalen der Physik 17, 891 (1905); D. Habs et al., Appl. Phys. B 93, 349 (2008)] brilliant high-energy photon beams with \(\hbar\omega^{\prime}=4\tilde{\gamma}^2\hbar\omega\) and short duration for many new nuclear physics experiments.While the shortest-lived atomic levels are in the atto-second range, nuclear levels can have lifetimes down to zeptoseconds. We discuss how the modulation of electron energies in phase-locked laser fields used for as-measurements [E. Goulielmakis et al., Science 317, 769 (2007)] can be carried over to the new direct measurement of fs–zs nuclear lifetimes by modulating the energies of accompanying conversion electrons or emitted protons. In the field of nuclear spectroscopy we discuss the new perspective as a function of increasing photon energy. In nuclear systems a much higher sensitivity is predicted to the timevariation of fundamental constants compared to atomic systems [V. Flambaum, arXiv:nucl-th/0801.1994v1 (2008)]. For energies up to 50 keV Mössbauer-like recoilless absorption allows to produce nuclear bosonic ensembles with many delocalized coherent polaritons [G.V. Smirnov et al., Phys. Rev. A 71, 023804 (2005)] for the firsttime. Using the (γ,n) reaction to produce cold, polarized neutrons with a focusing ellipsoidal device [P. Böni, Nucl. Instrum. Meth. A 586, 1 (2008); Ch. Schanzer et al., Nucl. Instrum. Meth. 529, 63 (2004)], brilliant cold polarized micro-neutron beams become available. The compact and relatively cheap laser-generated γ beams may serve forextended studies at university-based facilities.     

An Alternative Approach to Understanding the Observed Positron Fraction

Space-based observations by PAMELA (Adriani et al., Nature 458, 607, 2009), Fermi-LAT (Ackerman et al., Phys. Rev. Lett. 105, 01103, 2012), and AMS (Aguilar et al., Phys. Rev. Lett. 110, 141102, 2013) have demonstrated that the positron fraction (e+/total-e) increases with increasing energy above about 10 GeV. According to the propagation model for Galactic cosmic rays in widespread use (Moskalenko & Strong, Astrophys. J. 493, 693, 1998), the production of secondary positrons from interaction of cosmic-ray protons and heavier nuclei with the interstellar medium gives a generally falling positron fraction between 10 and 100 GeV, with secondary positrons accounting for only ～20 % of the observed positron fraction at 100 GeV; so some other physical phenomena have been proposed to explain the data. An alternative approach to interpreting the positron observations is to consider these data as presenting an opportunity for re-examining models of Galactic cosmic-ray propagation. Following release of the PAMELA data, three groups published propagation models (Shaviv, et al., Phys. Rev. Lett. 103, 111302, 2009, Cowsik and Burch, Phys. Rev. D. 82, 023009, 2010, Katz et al., Mon. Not. R. Aston. Soc. 405, 1458 2010) in which the observed positron fraction is explained entirely by secondary positrons produced in the interstellar medium. In May of this year, stimulated by the AMS extension of the positron data to higher energy with excellent statistics, two of those groups presented further development of their calculations (Cowsik et al. 2013, Blum et al. 2013), again concluding that the observed positrons can be understood as secondaries. None of the authors of these five papers was registered for the 33rd International Cosmic Ray Conference (ICRC). Although I am not an author of any of these papers, I have some close familiarity with one of these recent papers, so the conference organizers invited me to bring this alternative approach to the attention of the conference. The present paper is a summary of the material I presented, along with a brief comment about reaction at the conference to this approach.     

Volume reflection and volume refraction of relativistic particles in a uniformly bent crystal

The scattering of fast charged particles in a bent crystal has been analyzed in the framework of relativistic classical mechanics. The expressions obtained for the deflection function are in satisfactory agreement with the experimental data for the volume reflection of relativistic protons obtained by Yu. M. Ivanov et al., Phys. Rev. Lett. 97, 144801 (2006); Yu. M. Ivanov et al., Pis’ma Zh. Eksp. Teor. Fiz. 84, 445 (2006) [JETP Lett. 84, 372 (2006)]; and W. Scandale et al., Phys. Rev. Lett. 98, 154801 (2007). The features of the scattering of the particles on ring potentials are considered in a wide range of impact parameters.     

Observation of quantum noise in the polarization of laser light in a rubidium-vapor cell

Experimental observation of quantum noise in the polarization of laser light that has passed through a dense Rb⁸⁷ atomic vapor is reported. The step-like noise spectrum is observed. Factors responsible for the form of the observed spectrum and the absence of noise “squeezing” predicted by Matsko et al. [Phys. Rev. A 63, 043814 (2001)] are discussed.     

Asymptotics of work distributions in a stochastically driven system

We determine the asymptotic forms of work distributions at arbitrary times T, in a class of driven stochastic systems using a theory developed by Nickelsen and Engel (EN theory) [D. Nickelsen and A. Engel, Eur. Phys. J. B 82, 207 (2011)], which is based on the contraction principle of large deviation theory. In this paper, we extend the theory, previously applied in the context of deterministically driven systems, to a model in which the driving is stochastic. The models we study are described by overdamped Langevin equations and the work distributions in path integral form, are characterised by having quadratic augmented actions. We first illustrate EN theory, for a deterministically driven system – the breathing parabola model, and show that within its framework, the Crooks fluctuation theorem manifests itself as a reflection symmetry property of a certain characteristic polynomial, which also determines the exact moment-generating-function at arbitrary times. We then extend our analysis to a stochastically driven system, studied in references [S. Sabhapandit, EPL 89, 60003 (2010); A. Pal, S. Sabhapandit, Phys. Rev. E 87, 022138 (2013); G. Verley, C. Van den Broeck, M. Esposito, New J. Phys. 16, 095001 (2014)], for both equilibrium and non-equilibrium steady state initial distributions. In both cases we obtain new analytic solutions for the asymptotic forms of (dissipated) work distributions at arbitrary T. For dissipated work in the steady state, we compare the large T asymptotic behaviour of our solution to the functional form obtained in reference [New J. Phys. 16, 095001 (2014)]. In all cases, special emphasis is placed on the computation of the pre-exponential factor and the results show excellent agreement with numerical simulations. Our solutions are exact in the low noise (β →?∞) limit.