If you solve the 1D time independent schrodinger equation for a system with V(x)=0, you get a solution like:(adsbygoogle = window.adsbygoogle || []).push({});

Ψ(x) = Aexp(ikx) + Bexp(-ikx)

Applying certain boundary conditions would give you the solution to the Simple harmonic oscillator or infinite well etc. But I often see the wavefunction for a free particle written as

Ψ(x) = Aexp(ikx)

So is there some boundary condition which causes B=0 ?

I have tried the periodic BC Ψ(0) = Ψ(L) and dΨ/dx (x=0) = dΨ/dx (x=L) but this only seems to give me certain values of k, it does nothing with A or B.

I see that each term represents a wave in each direction, but I dont see how the B is lost if we start with the Schrodinger equation. I am under the impression that periodic boundary conditions result in the solution Ψ(x) = Aexp(ikx) but cant get rid of my B..

Thanks

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Basic QM question: Why do we describe free particles using Aexp(ikx) ?

Loading...

Similar Threads - Basic question describe | Date |
---|---|

I Generalized coordinates basic question | Feb 24, 2018 |

B Some very basic questions around the double slit experiment | Sep 25, 2017 |

B Basic question about double slit interferance | Feb 24, 2017 |

I Early Quantum Entanglement Experiments basic question? | Jan 21, 2017 |

B Bell's Theorem basic question on contextuality & locality | Jan 16, 2016 |

**Physics Forums - The Fusion of Science and Community**