Does anyone know of a direct quantum algorithm for computing GCD, - There could be quantum gates for addition subtraction constructed explicitly, using CNOT, etc. - the construction can be done in some poly(n) of input, (this is just a guess), but is there any algorithm, scheme for computing GCD, using quantum algorithms, gauss sums, QFT, quantum approximation, anything(!!) thanks, 
A quantum algorithm for GCD
approximation algorithms;quantum computing