Quantum mechanics question

1. Jul 24, 2010

Yedi

Why is there, for a free particle no physical state, i.e, proper wave function, for a negative energy?

Is it because k is imaginary? (k = sqrt(-2mE)/(reduced Planck's constant)

2. Jul 24, 2010

kuruman

Don't forget that, for a free particle, the potential energy is implicitly V = 0. Can a free particle exist in a state where its energy E is everywhere in space less than its potential energy? What does the Schrodinger equation have to say about that?

3. Jul 24, 2010

Dickfore

Because those states are not normalizable.

4. Jul 24, 2010

Sure.