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Quantum tunnelling is a phenomenon of non-equilibrium quantum dynamics and its detailed process is largely unexplored. We report the experimental observation of macroscopic quantum tunnelling of Bose–Einstein condensate in a hybrid trap. By exerting a non-adiabatic kick to excite a collective rotation mode of the trapped condensate, a periodic pulse train, which remains as condensate, is then out-coupled by quantum tunnelling. This non-equilibrium dynamics is analogue to tunnelling ionization. The imaged tunnelling process shows the splitting of matter wave packet by the potential barrier. The controversial "tunnelling time" question is found inadequate, from the point of view of wave propagation. The realized matter wave pulse train can also be a passive pulsed atom laser for atom interferometer applications. Quantum tunnelling as a non-equilibrium process is a problem of quantum physics that has been investigated in several microscopic systems. Motivated by attosecond ionization experiments and the puzzle of tunnelling time, the authors report experimental results on the quantum tunnelling of a Bose–Einstein Condensate out of an optical dipole trap. [ABSTRACT FROM AUTHOR]

Quantum discord, a measure of quantum correlation beyond entanglement, is initially defined as the discord between two classically equivalent while quantum discordant definitions of mutual information. In this paper, we report some new interpretations of discord which rely on the differences between measurement-induced effects on the local measured system and the whole system. Specifically, with proper quantitative definitions introduced in Buscemi et al (2008 Phys. Rev. Lett. 100 210504), we find that quantum discord can be interpreted as the differences of measurement-induced disturbance or information gain on the local measured system and on the whole system. Combined with previous similar results based on measurement-induced entanglement and decoherence, our results provide a unified view on quantum discord. [ABSTRACT FROM AUTHOR]

The mass neutrino interference phase in a global monopole space time along the null trajectory and the geodesic is studied, and we find that the conserved energy changes a factor when a particle travels along the geodesic, if compared with the energy in the space time without the global monopole. The oscillation phase is increased by a factor due to the correction of the global monopole, comparing with the case in Schwarzschild space time. We obtain that the type-I phase along both the null and geodesic has a difference of a factor of 1−8 π η2, and that the phase along the geodesic is the double of that along the null. [ABSTRACT FROM AUTHOR]

The understanding of possible role played by the inner horizon of black holes in black hole thermodynamics is still somewhat incomplete. By adopting Damour-Ruffini method and the thin film model which is developed on the base of brick wall model suggested by ’t Hooft, we calculate the temperature and the entropy of the inner horizon of a R-N black hole. We conclude that the temperature of inner horizon is positive and the entropy of the inner horizon is proportional to the area of the inner horizon. In addition, the cut-off factor is 90 β, which is same in calculation of the entropy of the outer horizon. So, we prove the existence of thermal characters of the inner horizon. Then, we discuss that if the contribution of the inner horizon is taken into account to the total entropy of the black hole, the Nernst theorem can be satisfied. At last, we study the tunneling effect including the inner horizon of the Reissner-Nordstrom black hole. We calculate the tunneling rate of the outer horizon Γ+ and the inner horizon Γ−. The total tunneling rate Γ should be the product of the rates of the outer and inner horizon, Γ=Γ+⋅Γ−. We find that the total tunneling rate is in agreement with the Parikh’s standard result, Γ→exp (Δ S BH), and there is no information loss. [ABSTRACT FROM AUTHOR]

Electrostatic drift waves in a nonuniform quantum magnetized electron-positron (pair) plasma are investigated. An explicit and straightforward analytical expression of the fluctuation frequency is presented. The effects induced by quantum fluctuations, density gradients, and magnetic field inhomogeneity on the wave frequencies are discussed and a purely quantum drift mode appears. The present analytical investigations are relevant to dense astrophysical objects as well as laboratory ultracold plasmas. [ABSTRACT FROM AUTHOR]

In this paper, we prove a stronger entanglement monogamy inequality in a 2[?]2[?]3 system's pure state |Ps[?]ABC. Specifically, we show that the linear entropy of rA, which is the entanglement between A and BC, is always larger than the sum of the square of concurrence between A and B and the square of concurrence of assistance between A and C. Our proof is based on direct generalizations of the qubit system's results. Our inequality is stronger than the known monogamy inequality of concurrence and shows that the entanglement of assistance always comes from the existing entanglement. However, our inequality also shows that unlike the three-qubit case, in higher dimensional systems the entanglement between A and BC cannot be completely transformed into bipartite entanglement with assistance. Through our proof, we also give some cases when the inequality reduces to an equality. [ABSTRACT FROM AUTHOR]