4 papers
Can a spin-half particle ever give more than two spots in a Stern-Gerlach experiment? -- the subtle physics of effective Hamiltonians
Noah Linden, Sandu Popescu, Anthony J. Short
We show that a spin-1/2 particle can behave as if it were spin-, and generate spots in a Stern Gerlach measurement (albeit with a smaller gyromagnetic ratio). This arises…
Recurrence Time for Finite Quantum Systems
Chaitanya Gupta, Anthony J. Short
We study the time it takes for all states of a finite quantum system to return simultaneously to their original configuration. In particular, we define the recurrence time for a qu…
Fermion Doubling in Dirac Quantum Walks
Chaitanya Gupta, Anthony J. Short
We consider discrete spacetime models known as quantum walks, which can be used to simulate Dirac particles. In particular we look at fermion doubling in these models, in which hig…
The Dirac Vacuum in Discrete Spacetime
Chaitanya Gupta, Anthony J. Short
We consider introducing the Dirac sea in a quantum cellular automata model of fermions in discrete spacetime which approximates the Dirac equation in the continuum limit. However,…