i cannot understand why persistent current in a normal metal ring threaded by a magnetic field is a surprise.(adsbygoogle = window.adsbygoogle || []).push({});

the hamiltonian is

[tex]H=\frac{1}{2I}\left(-i \frac{\partial}{\partial \theta}-A\right)^2[/tex]

and the eigenstates are

[tex]\phi_m(\theta)=\frac{1}{\sqrt{2\pi}} e^{i m \theta}[/tex]

with eigenvalues

[tex]E_m=\frac{1}{2I}(m-A)^2[/tex].

It is ready to see that generally every eigenstate carries a current, a persistent one.

so why people think it is a surprise?

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# Why pesistent current in a normal metal ring is a surprise?

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