1. Abstraction of Deutsch Algorithm and Its Implementation on QCL

2. Quantum Computer in Present  Many researchers have been tried to implement Quantum Computer from 1990s.  First quantum computer is demonstrated  At Supercomputing 2007 Conference  It’s said it’s not perfect quantum computer  But it’s definitely faster  http://kr.youtube.com/watch?v=pzFTXYJ2J1I http://kr.youtube.com/watch?v=pzFTXYJ2J1I  http://kr.youtube.com/watch?v=OgcTK29QeA0 http://kr.youtube.com/watch?v=OgcTK29QeA0

3. Deutsch’s Algorithm  Deutsch’s algorithm is  Proposed by Prof. David Deutsch of Oxford  On his homepage, http://www.qubit.org/people/david/, he provided int roductory video lectures on quantum computinghttp://www.qubit.org/people/david/  The first one that proved quantum computer is faster

4. Deutsch’s Algorithm  Oracle function  Goal of the algorithm  Determine is constant or balanced  Constant: or  Balanced: or

5. Deutsch’s Algorithm  Qubit representation (modified) 1 0 1 0 |0> 1 0 |0> + |1> 1 0 |0> +

6. Deutsch’s Algorithm  Hadamard Transform (Operator or Gate) 1 0 |0> 1 0 |1>|0> +

7. Deutsch’s Algorithm  Hadamard Transform (Operator or Gate) 1 0 |1>|0> 1 0 |1>

8. Deutsch’s Algorithm  Oracle function  Goal of the algorithm  Determine is constant or balanced  Constant: or  Balanced: or

9. Deutsch’s Algorithm  Quantum Circuit Design  Measurement  If result is 0, is constant  If result is 1, is balanced |0> |1> Measure

10. Deutsch’s Algorithm  Case 1: |0> |1> |0>

11. Deutsch’s Algorithm  Case 2: |0> |1> |0>

12. Deutsch’s Algorithm  Case 3: |0> |1>

13. Deutsch’s Algorithm  Case 4: |0> |1>

14. Deutsch’s Algorithm  Implementation on QCL – main function procedure main() { qureg x[1]; qureg y[1]; int m; { reset; U(x, y); measure y, m; } until m == 1; measure x,m; print "g(0) xor g(1) =", m; reset; }

15. Deutsch’s Algorithm  Implementation on QCL – U operator operator U(qureg x, qureg y) { H(x); H(y); F(x, y); H(x); } |0> |1> Measure

16. Deutsch’s Algorithm  Implementation on QCL – F and f function const coin1=(random()>=0.5); const coin2=(random()>=0.5); // result boolean g(boolean x) { if coin1return coin2; // constant return x xor coin2; // balanced } qufunct F(quconst x, quvoid y) { if f(0) xor f(1) CNot(y,x); if f(0) Not(y); }

17. Deutsch’s Algorithm  Discussion  Call by Value? or Call by Reference?  Local variable for qubit is valid?  Qubits cannot be cloned  Measuring operation destroys qubit to simple boolean value  Measuring cannot be placed in an iteration  Conclusion  QCL is more like hardware simulator, not programming lang.  It just looks like C such as FPGA design languages