Vladislav V Kravchenko 2005 J. Phys. A: Math. Gen. 38 851 doi:10.1088/0305-4470/38/4/006
Vladislav V Kravchenko
Show affiliationsGiven a particular solution of a one-dimensional stationary Schrödinger equation this equation of second order can be reduced to a first-order linear ordinary differential equation. This is done with the aid of an auxiliary Riccati differential equation. In the present work we show that the same fact is true in a multidimensional situation also. For simplicity we consider the case of two or three independent variables. One particular solution of the stationary Schrödinger equation allows us to reduce this second-order equation to a linear first-order quaternionic differential equation. As in the one-dimensional case this is done with the aid of an auxiliary quaternionic Riccati equation. The resulting first-order quaternionic equation is equivalent to the static Maxwell system and is closely related to the Dirac equation. In the case of two independent variables it is the well-known Vekua equation from theory of pseudoanalytic (or generalized analytic) functions. Nevertheless, we show that even in this case it is very useful to consider not only complex valued functions, solutions of the Vekua equation, but complete quaternionic functions. In this way the first-order quaternionic equation represents two separate Vekua equations, one of which gives us solutions of the Schrödinger equation and the other one can be considered as an auxiliary equation of a simpler structure. Moreover for the auxiliary equation we always have the corresponding Bers generating pair (F, G), the base of the Bers theory of pseudoanalytic functions, and what is very important, the Bers derivatives of solutions of the auxiliary equation give us solutions of the main Vekua equation and as a consequence of the Schrödinger equation. Based on this fact we obtain an analogue of the Cauchy integral theorem for solutions of the stationary Schrödinger equation. Other results from theory of pseudoanalytic functions can be written for solutions of the Schrödinger equation. Moreover, for an ample class of potentials in the Schrödinger equation (which includes for instance all radial potentials), this new approach gives us a simple procedure allowing us to obtain an infinite sequence of solutions of the Schrödinger equation from one known particular solution.
30G20 Generalizations of Bers or Vekua type (pseudoanalytic, p-analytic, etc.)
Issue 4 (28 January 2005)
Received 17 August 2004, in final form 19 November 2004
Published 12 January 2005
Vladislav V Kravchenko 2005 J. Phys. A: Math. Gen. 38 851
Arthur E Fischer 2004 Class. Quantum Grav. 21 S171
M.-A. Arrio et al 2000 Europhys. Lett. 51 454
K Gelin and E Wäckelgård 2004 J. Phys.: Condens. Matter 16 833
Daniel Gottesman and John Preskill JHEP03(2004)026
S V S Narayana Murty et al 2002 Modelling Simul. Mater. Sci. Eng. 10 503
Jong H Chow et al 2004 Class. Quantum Grav. 21 S909
Brien C Nolan 1999 Class. Quantum Grav. 16 1227
Gerhard Nägele 2003 J. Phys.: Condens. Matter 15 S407
Urs Schreiber JHEP05(2004)027