Three sets of exactly solvable one-dimensional quantum mechanical potentials are presented. These are shape invariant potentials obtained by deforming the radial oscillator and the trigonometric/hyperbolic Pöschl-Teller potentials in terms of their degree l polynomial eigenfunctions. We present the entire eigenfunctions for these Hamiltonians (l = 1, 2, . . .) in terms of new orthogonal polynom...

The magnetic structure of LaMnO3 is investigated on three-dimensional clusters of MnO6 octahedra by using a combination of relaxation and Monte Carlo techniques. It is found that the cooperative Jahn-Teller phonons lead to the stabilization of A-type antiferromagnetic and C-type orbital structures in the physically relevant region of parameter space for LaMnO3 with small corrections due to tilt...

Oxygen isotope effect studies of the ferromagnetic Curie temperature Tc of La1AxCaxMnO3 are presented. The isotope exponent α0G−∆ ln Tcy∆ ln m0 changes from 0.4 to 0.14 in the range 0.2FxF0.43. The isotope exponent decreases strongly with increasing tolerance factor, or decreasing lattice distortion. Above Tc the conductivity is characteristic of small polarons. Raman scattering shows a promine...

The eg-orbital states with complex coefficients of the linear combination of x2 − y2 and 3z2 − r2 are studied for the ferromagnetic state in doped manganites. Especially the focus is put on the competition among uniform complex, staggered complex, and real orbital states. As the hole-doping x increases, the real, the canted complex, and the staggered complex orbital states appears successively....

Continuum effects in the weakly bound nuclei close to the drip-line are investigated using the analytically soluble Pöschl-Teller-Ginocchio potential. Pairing correlations are studied within the Hartree-Fock-Bogoliubov method. We show that both resonant and non-resonant continuum phase space is active in creating the pairing field. The influence of positive-energy phase space is quantified in t...

Starting from a spin-orbital model for doped manganites, we investigate a competition between ferromagnetic and antiferromagnetic order in a one-dimensional model at finite temperature. The magnetic and orbital order at half filling support each other and depend on a small antiferromagnetic superexchange between t2g spins and on an alternating Jahn-Teller potential. The crossover to a metallic ...

A u n i t a r y t rans format ion is appl ied to the E-e J a h n T e l l e r problem. T h e eigenfunctions of the diagonal par t of the t r a n s f o r m e d H a m i l t o n i a n are uti l ized for a R i t z diagonal izat ion procedure. R e s u l t s are g i v e n for basic sets of 1 2 , 20 and 42 funct ions and compared with the respect ive conventional ca lculat ions . I n the t r a n s f o ...

The dynamical Jahn-Teller effect on fullerene sites in insulating Cs(3)C(60) is investigated fully ab initio. The vibronic excitations of rotational type are at ≥ 65 cm(-1), while the net kinetic contribution to the Jahn-Teller stabilization energy constitutes approximately 90 meV. This means that no localization of distortions by intermolecular interactions is possible in these fullerides; the...

We present energy spectrum calculations of 5E term of Fe++ ion taking into account crystal field, spin-orbit interaction, uniaxial stress, magnetic field and dynamic Jahn-Teller effect. Basing on the obtained energy spectra we calculate magnetic properties (specific heat and magnetization) of Fe-based Semimagnetic Semiconductors. We found that presence of the JahnTeller effect has very small in...

We propose a group-theoretical approach to the generalized oscillator algebra Aκ recently investigated in J. Phys. A: Math. Theor. 2010, 43, 115303. The case κ ≥ 0 corresponds to the noncompact group SU(1,1) (as for the harmonic oscillator and the Pöschl-Teller systems) while the case κ < 0 is described by the compact group SU(2) (as for the Morse system). We construct the phase operators and t...