Quantum Computing Basic Concepts and Applications

What is Quantum Computing?  Conventional computers use bits  Quantum computers use “qubits” –Can be both 0 and 1 at once –When measured, “snaps” into either 0 or 1 –Coefficient marks the probability of which state the qubit will “snap” into

Quantum Interference: An Experiment

Implications of Superposition  Each register holds all possible values

Implications of Superposition  Computation is massively parallel  4-qubit register holds all 2 4 values  Running a function on the register is like that function running on all possible values within the register –This would take 2 4 times longer on a conventional computer

Problems  Decoherence –Computation spreads across close matter –Superpositions spread, thus degrading the computation  Hardware –Purdue scientists created “quantum transistor”

Applications  Massively parallel computation allows –Breaking of RSA –Solving previously NP-complete problems  Quantum encryption –Light beam cannot be intercepted without destroying the message (Heisenberg Uncertainty Principle)

Quantum Teleportation

 Subatomic particles “intertwined”  When one “flips,” its partner does too  Allows instantaneous communication that appears to be incapable of interception

Conclusions  Quantum Computing is massively powerful –Massively parallel computation  Can break RSA  Opens up doors to new forms of encryption  Allows a new type of information transmission