But, in a recent breakthrough, the scientists from the University of New South Wales in Sydney, Australia and led by Andrew Dzurak have used two silicon transistors as the qubits (quantum bits) to perform a very simple calculation. Well, that is certainly an achievement considering the intricacies involved in quantum computing.
Building a quantum computer is quite a difficult task as the qubits keep on changing their states (0,1) and hence a comprehensive probabilistic measures are adopted for the measurements. Moreover, the system needs to be isolated to reduce decoherence, i.e. the loss of information to the environment.
The above dynamic scenario is easily represented by the atoms, but to do so with Silicon transistors is remarkable. The researchers have created a two-qubit logic gate in silicon and have been successful in reading out both the qubits with a switchable exchange interaction in the two-qubit controlled-phase gate.
The scientists created a CNOT gate (a quantum gate) and measured the anticorrelations in the two-spin probabilities of the electrons. Simply stated, the device looks at the spin of two electrons and if one is spinning in a particular direction then the second electron flips its spin. If not, then nothing happens.
Now, when the basic CNOT is scaled by millions, a real quantum chip comes out that can perform complex calculations. The silicon based qubits have one advantage over the existing technology that they are easier to scale up.
Although, this technology will require even more time to develop and dominate the already prevailing D-Wave technology which is adopted by the NASA and Google. Dzurak, however, believes his team is five years away from building a working processor.