Seminar on Quantum Computing
Status ofQuantum Computing
• Computinggiants Google and Microsoft recently hired a host of leading lights, and haveset challenging goals in QC (Nature news 2017)
• D-Wave2000Q – the firm’s first 2,000 quantum bit (qubit) quantum computer came toexistence in 2017
– Thequantum 2000Q is capable of outperforming “classical servers” by factors ofbetween 1,000 and 10,000
– IBMestablished a landmark in computing Friday, announcing a quantum computer thathandles 50 quantum bits, or qubits
– Thecompany is also making a 20-qubit system available through its cloud computingplatform
– Scalingup to hundreds or thousands of quantum bits becomes a possibility
• QuantumCommunication
– Teleportation, Entanglement and Zeno Effecthas been successfully implemented and tested
• QuantumCryptography
– QuantumKey Exchange Protocols, BB84 etc.
• QuantumMachine Learning
– QuantumClustering, Quantum Random Walk Algorithms for Heuristic Search
• Qubitvs. Bit:
Bit (Classical) degree of freedom that can take only twopossible values.
– Qubit
• Quantumobservable whose spectrum contains two values {0,1}.
• Minimalquantum physical system.
• Theboolean observable of a qbit system is called a sharp observable , as it canhave only values 0 and 1.
• Aqubit can have another observable which has an equal probability of 1 and 0,individual probabilities summed will results to unity.
• Qubitin reality:
– Electronspin (up or down)
– Photonpolarization (horizontal/vertical)
– Spinof atomic nucleus
– Currentin a super conducting loop
– Presence/absenceof a particle
