Logic gates and illogic thrusts in quantum computing.

Quantum computer is probably the most prominent subject of quantum physics. Reason is obvious. While all the mystifying test results in quantum mechanics only seem to bug people's minds, quantum computers would put all this confusing potential to maximum benefit. Increasing endeavor to produce quantum computers has already grasped mainstream public attention, which is not very commonplace situation for futuristic technology. Even some people who don't have any particular interest in physics may have heard of qcs and started to adapt the idea. This may result less than usual resistance towards this new technology once it appears.

Early acceptance towards qc would be beneficial to everyone.*

Computers we use today speed up almost constant rate. In the progress bulgy relays has transformed to notably large vacuum tubes to sole transistors and to integrated circuits holding many transistors in a single chip. And while still integrated circuits are the building bricks of modern computers, Moore's law has pretty accurately predicted that amount of transistors on integrated circuits doubles every two year. Key feature to achieve this has been the size. Technology manufacturers has been able to miniaturize transistors so that more and of them will fit into single chip. This very handsome trend has unfortunately limits however, one of the most obvious one is that when transistor reaches size of an atom it cannot be divided into smaller pieces. More likely that small transistors won't be ever be achieved, because when the quantum rules begins to place in the small realm of tiniest chipsets, whole new formation of rules and phenomenons are required to be considered in the manufacturing process.

Classical transistors themselves act as logic gates in computer chips. Logic gates are like small counters who can count to two using Boolean algebra. Well, to tell difference between values 0 and 1 to be accurate. These values could represent basically any physical property that can be measured, voltage of electrical current for example (≥5V = 0; 7V≥= 1). There are many different kind of gates available, but ordinary computer doesn't have to have all of them in order to be universal (universal means it can compute any possible binary code). Quantum computers would have to have major difference in it's logic gates, since data wouldn't be processed in any certain state using quantum bits (quantum bits = qubits I mentioned in my previous text).

AND logic gate's and NOT gate's truth tables. AND gives out 1 if both inputs are 1, otherwise it gives 0. NOT gate always changes input, therefore it is common called inverter.

Notice how you could guess what was the input in NOT-gate if you knew only output? Well same is not with AND-gate. You cannot tell if A or B both were 0 or if only one of them was 1 if output is 0 You loose some information when you move from input to output. Logic gates in quantum computing would have this thing differently and it's one the reasons why theoretically qc is faster than ordinary computer. However it would be faster only in some processes and not so smooth in others. Much like an airplane is faster so long as it stays airborne.

Early qc pioneer Edward Fredkin came up with idea for logic gate for qc. Fredkin had a dream of building a reversible computer and he realized that this can be achieved if no information is lost in a logic gate. Truth table in Fredkin gate looks confusing at first, put if you pay attention to it, you'll notice that c value never changes when it move trough the gate. Also notice other two values p and q don't change when c = 0, and they switch places if c=1. Fredkin gate is universal and completely reversible.

Fredkins gate is an example of logic gate in quantum computer.

When I wrote Fredkins gate is reversible, it means that it can undone itself without consuming resources. This is not possible with ordinary transistors. However if qc is build to use physical properties that are entangled, like spin or polarization, it is possible to have logic gates that puts spooky action at a distance into better use than confusing Einstein. Swapping from input to output and from output to input without consuming time or energy, quantum computer could provide answers to questions which are presently thought to be unsolvable, thrusting mankind's capabilities into new highs, beyond quantum barriers which seem to separate our world from another, smaller, but more potential one.