Pöschl–Teller potential

In mathematical physics, a Pöschl–Teller potential, named after the physicists Herta Pöschl{{Cite web |url=https://e-reports-ext.llnl.gov/pdf/376159.pdf |title="Edward Teller Biographical Memoir." by Stephen B. Libby and Andrew M. Sessler, 2009 (published in Edward Teller Centennial Symposium: modern physics and the scientific legacy of Edward Teller, World Scientific, 2010. |access-date=2011-11-29 |archive-url=https://web.archive.org/web/20170118171614/https://e-reports-ext.llnl.gov/pdf/376159.pdf |archive-date=2017-01-18 |url-status=dead }} (credited as G. Pöschl) and Edward Teller, is a special class of potentials for which the one-dimensional Schrödinger equation can be solved in terms of special functions.

Definition

In its symmetric form is explicitly given by{{Cite journal | last1 = Pöschl | first1 = G. | last2 = Teller | first2 = E. | doi = 10.1007/BF01331132 | title = Bemerkungen zur Quantenmechanik des anharmonischen Oszillators | journal = Zeitschrift für Physik | volume = 83 | issue = 3–4 | pages = 143–151 | year = 1933 |bibcode = 1933ZPhy...83..143P | s2cid = 124830271 }} Image:Poschl-Teller_potential.svg

:

V(x) =-\frac{\lambda(\lambda+1)}{2}\mathrm{sech}^2(x)

and the solutions of the time-independent Schrödinger equation

:

-\frac{1}{2}\psi''(x)+ V(x)\psi(x)=E\psi(x)

with this potential can be found by virtue of the substitution u=\mathrm{tanh(x)}, which yields

:

\left[(1-u^2)\psi'(u)\right]'+\lambda(\lambda+1)\psi(u)+\frac{2E}{1-u^2}\psi(u)=0

.

Thus the solutions \psi(u) are just the Legendre functions P_\lambda^\mu(\tanh(x)) with E=-\frac{\mu^2}{2}, and \lambda=1, 2, 3\cdots, \mu=1, 2, \cdots, \lambda-1, \lambda. Moreover, eigenvalues and scattering data can be explicitly computed.Siegfried Flügge Practical Quantum Mechanics (Springer, 1998) In the special case of integer \lambda, the potential is reflectionless and such potentials also arise as the N-soliton solutions of the Korteweg–De Vries equation.{{Cite journal | last1 = Lekner | first1 = John | doi = 10.1119/1.2787015 | title = Reflectionless eigenstates of the sech2 potential | journal = American Journal of Physics | volume = 875 | issue = 12 | pages = 1151–1157 | year = 2007|bibcode = 2007AmJPh..75.1151L }}

The more general form of the potential is given by

:

V(x) =-\frac{\lambda(\lambda+1)}{2}\mathrm{sech}^2(x) - \frac{\nu(\nu+1)}{2}\mathrm{csch}^2(x) .

Rosen–Morse potential

A related potential is given by introducing an additional term:{{Cite journal|last1=Barut|first1=A. O.|last2=Inomata|first2=A.|last3=Wilson|first3=R.|date=1987|title=Algebraic treatment of second Poschl-Teller, Morse-Rosen and Eckart equations|url=http://stacks.iop.org/0305-4470/20/i=13/a=017|journal=Journal of Physics A: Mathematical and General|language=en|volume=20|issue=13|pages=4083|doi=10.1088/0305-4470/20/13/017|issn=0305-4470|bibcode=1987JPhA...20.4083B}}

:

V(x) =-\frac{\lambda(\lambda+1)}{2}\mathrm{sech}^2(x) - g \tanh x.

See also

References list

{{Reflist}}