Digital Computers rely on binary digits, known as bits, to represent data - that is, zeros and ones, which represent either an on or off that is acts like language to the computer. On the other hand, Quantum Computers use quantum bits, or qubits, which are both on and off at the same time. This allows quantum computers to calculate two calculations at any given time, and this number only rises with the number of qubits a computer has.
Scientists at Google and a few of their partners believe that they are getting much closer to the perfection of a quantum computer, according to Inside Science. The publication notes that a quantum computer with just 300 qubits is capable of solving more problems than there are atoms in the universe, so the completion of such will advance the reach of science exponentially.
According to Nature.Com, scientists from Google and physicists at the University of California have started on a device that combines the two approaches to quantum computation.
There are two main ways at which quantum computation is exercised - one which is called the Gate Model and the other that uses Adiabatic Quantum Computing. The former links up qubits into circuits, which can perform basic operations. One tunes each qubit to a given setting, another manipulates the qubits within a quantum algorithm, and another scans the system for an answer. In other words, there is a construction of digital circuits using qubits in particular arrangements to solve a specific problem.
The latter of the two is a bit more controversial.
In Adiabatic Quantum Computation, the qubits start of at their ground state, before being carefully evolved into a set of qubits, whose interaction at the ground state represents the correct answer. This is controversial in the sense that many scientists find this means to be much like the average computer and there is also the risk of errors due to random noise.
What Google is doing now is using a row of nine-solid state qubits from cross-shaped films of aluminum, which are left on a sapphire surface.When the qubits are in their superconducting state, information can be encoded into them. The interactions between the qubits are controlled by "logic gates" that somehow digitally steer the qubits into a state that provides the answer.
While this may seem a little simple, the Google team claims that their device can also handle "non-stoquastic' problems, which the average computer cannot solve. In order to do so, a simulation is created of the interactions between electrons, which is tantamount for accuracy.
According to Alireza Shabani, a member of the Google team, "With error correction, our approach becomes a general-purpose algorithm that is, in principle, scalable to an arbitrarily large quantum computer."
