ترغب بنشر مسار تعليمي؟ اضغط هنا

Dynamics of a one-dimensional spinor Bose liquid: a phenomenological approach

75   0   0.0 ( 0 )
 نشر من قبل Leonid Glazman
 تاريخ النشر 2009
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

The ground state of a spinor Bose liquid is ferromagnetic, while the softest excitation above the ground state is the magnon mode. The dispersion relation of the magnon in a one-dimensional liquid is periodic in the wavenumber q with the period 2pi n, determined by the density n of the liquid. Dynamic correlation functions, such as e.g. spin-spin correlation function, exhibit power-law singularities at the magnon spectrum, $omegatoomega_m(q,n)$. Without using any specific model of the inter-particle interactions, we relate the corresponding exponents to independently measurable quantities $partialomega_m/partial q$ and $partialomega_m/partial n$.

قيم البحث

اقرأ أيضاً

We show that the dynamic structure factor of a one-dimensional Bose liquid has a power-law singularity defining the main mode of collective excitations. Using the Lieb-Liniger model, we evaluate the corresponding exponent as a function of the wave vector and the interaction strength.
In this paper we review recent theoretical results for transport in a one-dimensional (1d) Luttinger liquid. For simplicity, we ignore electron spin, and focus exclusively on the case of a single-mode. Moreover, we consider only the effects of a sing le (or perhaps several) spatially localized impurities. Even with these restrictions, the predicted behavior is very rich, and strikingly different than for a 1d non-interacting electron gas. The method of bosonization is reviewed, with an emphasis on physical motivation, rather than mathematical rigor. Transport through a single impurity is reviewed from several different perspectives, as a pinned strongly interacting ``Wigner crystal and in the limit of weak interactions. The existence of fractionally charged quasiparticles is also revealed. Inter-edge tunnelling in the quantum Hall effect, and charge fluctuations in a quantum dot under the conditions of Coulomb blockade are considered as examples of the developed techniques.
91 - V. Pietila , M. Mottonen , 2007
We study the energetic and dynamic stability of coreless vortices in nonrotated spin-1 Bose-Einstein condensates, trapped with a three-dimensional optical potential and a Ioffe-Pritchard field. The stability of stationary vortex states is investigate d by solving the corresponding Bogoliubov equations. We show that the quasiparticle excitations corresponding to axisymmetric stationary states can be taken to be eigenstates of angular momentum in the axial direction. Our results show that coreless vortex states can occur as local or global minima of the condensate energy or become energetically or dynamically unstable depending on the parameters of the Ioffe-Pritchard field. The experimentally most relevant coreless vortex state containing a doubly quantized vortex in one of the hyperfine spin components turned out to have very non-trivial stability regions, and especially a quasiperiodic dynamic instability region which corresponds to splitting of the doubly quantized vortex.
The exact solutions of a one-dimensional mixture of spinor bosons and spinor fermions with $delta$-function interactions are studied. Some new sets of Bethe ansatz equations are obtained by using the graded nest quantum inverse scattering method. Man y interesting features appear in the system. For example, the wave function has the $SU(2|2)$ supersymmetry. It is also found that the ground state of the system is partial polarized, where the fermions form a spin singlet state and the bosons are totally polarized. From the solution of Bethe ansatz equations, it is shown that all the momentum, spin and isospin rapidities at the ground state are real if the interactions between the particles are repulsive; while the fermions form two-particle bounded states and the bosons form one large bound state, which means the bosons condensed at the zero momentum point, if the interactions are attractive. The charge, spin and isospin excitations are discussed in detail. The thermodynamic Bethe ansatz equations are also derived and their solutions at some special cases are obtained analytically.
85 - P-F Duc , M.Savard , M. Petrescu 2014
In one of the most celebrated examples of the theory of universal critical phenomena, the phase transition to the superfluid state of $^{4}$He belongs to the same three dimensional $mathrm{O}(2)$ universality class as the onset of ferromagnetism in a lattice of classical spins with $XY$ symmetry. Below the transition, the superfluid density $rho_s$ and superfluid velocity $v_s$ increase as power laws of temperature described by a universal critical exponent constrained to be equal by scale invariance. As the dimensionality is reduced towards one dimension (1D), it is expected that enhanced thermal and quantum fluctuations preclude long-range order, thereby inhibiting superfluidity. We have measured the flow rate of liquid helium and deduced its superfluid velocity in a capillary flow experiment occurring in single $30~$nm long nanopores with radii ranging down from 20~nm to 3~nm. As the pore size is reduced towards the 1D limit, we observe: {it i)} a suppression of the pressure dependence of the superfluid velocity; {it ii)} a temperature dependence of $v_{s}$ that surprisingly can be well-fitted by a powerlaw with a single exponent over a broad range of temperatures; and {it iii)} decreasing critical velocities as a function of radius for channel sizes below $R simeq 20$~nm, in stark contrast with what is observed in micron sized channels. We interpret these deviations from bulk behaviour as signaling the crossover to a quasi-1D state whereby the size of a critical topological defect is cut off by the channel radius.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا