Daily Archives: September 14, 2008

Quantum Cloning

It’s time I blogged some physics instead of filler like mouse transportation. There’s a lot of physics stuff going on around here but right now it’s kind of hush-hush and I can’t tell you about it. Which reminds me, I found an older version (perhaps a reader will disavow me of the notion that it is the oldest) of the line used in Top Gun, “I could tell you, but then I’d have to kill you“: Alexandre Dumas, in The Man in the Iron Mask aka The Vicomte de Bragelonne, writes:
“It is a state secret,” replied d’Artagnan, bluntly; “and as you know that according to the King’s orders it is under the penalty of death that any one should penetrate it, I will, if you like, allow you to read it and have you shot immediately afterwards.”

“The man in the iron mask” was a mysterious 17th century prisoner of the reign of Louis IV in France. Will I spoil the book if I tell you that in it, the state secret is that the man in the iron mask is the exact twin of the King of France? I hope not. It’s germane; in this post we will discuss what one would have to do to make the twin (or clone) of a quantum object, a [state] secret that evaded science until quite recently.

I will explain why this is of interest, and how this comes about in the language of quantum mechanics. For us, the quantum object will be an electron, and it’s state will be its spin.
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Filed under History, physics