Implementing the Deutsch's algorithm with spin-orbital angular momentum   of photon without interferometer
  Deutsch's algorithm is the simplest quantum algorithm which shows the acceleration of quantum computer. In this paper, we theoretically advance a scheme to implement quantum Deutsch's algorithm in spin-orbital angular momentum space. Our scheme exploits a newly developed optical device called "q-plate", which can couple and manipulate the spin-orbital angular momentum simultaneously. This experimental setup is of high stability and efficiency theoretically for there is no interferometer in it. 
Pei Zhang, Yan Jiang, Rui-Feng Liu, Hong Gao, Hong-Rong Li, and Fu-Li   Li
quant-ph