Zero-One is not enough
Description of Quantum Computer;
|| The Turing machine, developed by Alan Turing in the 1930s, is a theoretical device that consists of tape of unlimited length that is divided into little squares. Each square can either hold a symbol (1 or 0) or be left blank. A read write device reads these symbols and blanks, which gives the machine its instructions to perform a certain program. Does this sound familiar? Well, in a quantum Turing machine, the difference is that the tape exists in a quantum state, as does the read-write head. This means that the symbols on the tape can be either 0 or 1 or a superposition of 0 and 1; in other words the symbols are both 0 and 1 (and all points in between) at the same time. While a normal Turing machine can only perform one calculation at a time, a quantum Turing machine can perform many calculations at once.
Quantum computers aren't limited to two states; they encode information as quantum bits, or qubits, which can exist in superposition. Qubits represent atoms, ions, photons or electrons and their respective control devices that are working together to act as computer memory and a processor. Because a quantum computer can contain these multiple states simultaneously, it has the potential to be millions of times more powerful than today's most powerful supercomputers. This superposition of qubits is what gives quantum computers their inherent parallelism. T0his parallelism allows a quantum computer to work on a million computations at once, while your desktop PC works on one. A 30-qubit quantum computer would equal the processing power of a conventional computer that could run at 10 teraflops (trillions of floating-point operations per second). Today's typical desktop computers run at speeds measured in gigaflops (billions of floating-point operations per second).
Quantum computers also utilize another aspect of quantum mechanics known as entanglement. One problem with the idea of quantum computers is that if you try to look at the subatomic particles, you could bump them and thereby change their value. If you look at a qubit in superposition to determine its value, the qubit will assume the value of either 0 or 1, but not both (effectively turning your spiffy quantum computer into a mundane digital computer). To make a practical quantum computer, scientists have to devise ways of making measurements indirectly to preserve the system's integrity. Entanglement provides a potential answer. In quantum physics, if you apply an outside force to two atoms, it can cause them to become entangled, and the second atom can take on the properties of the first atom. So if left alone, an atom will spin in all directions. The instant it is disturbed it chooses one spin, or one value; and at the same time, the second entangled atom will choose an opposite spin, or value. This allows scientists to know the value of the qubits without actually looking at them.
Computer scientists control the microscopic particles that act as qubits in quantum computers by using control devices: Ion traps use optical or magnetic fields (or a combination of both) to trap ions, Optical traps use light waves to trap and control particles;
Quantum dots are made of semiconductor material and are used to contain and manipulate electrons; Semiconductor impurities contain electrons by using "unwanted" atoms found in semiconductor material and Superconducting circuits allowing electrons to flow with almost no resistance at very low temperatures.
Quantum computers could one day replace silicon chips, just like the transistor once replaced the vacuum tube. But for now, the technology required to develop such a quantum computer is beyond our reach. Most research in quantum computing is still very theoretical.
The most advanced quantum computers have not gone beyond manipulating more than 16 qubits, meaning that they are a far cry from practical application. However, the potential remains that quantum computers one day could perform, quickly and easily, calculations that are incredibly time-consuming on conventional computers.
To date, the two most promising uses for such a device are quantum search and quantum factoring. To understand the power of a quantum search, consider classically searching a phonebook for the name which matches a particular phone number. If the phonebook has 10,000 entries, on average you'll need to look through about half of them 5,000 entries before you get lucky. A quantum search algorithm only needs to guess 100 times. With 5,000 guesses a quantum computer could search through a phonebook with 25 million names.
Although quantum search is impressive, quantum factoring algorithms pose a legitimate, considerable threat to security. This is because the most common form of Internet security, public key cryptography, relies on certain math problems (like factoring numbers that are hundreds of digits long) being effectively impossible to solve. Quantum algorithms can perform this task exponentially faster than the best known classical strategies, rendering some forms of modern cryptography powerless to stop a quantum code-breaker.
Bits, either classical or quantum, are the simplest possible units of information. They are oracle-like objects that, when asked a question (i.e. when measured), can respond in one of only two ways. Measuring a bit, either classical or quantum, will result in one of two possible outcomes. At first glance, this makes it sound like there is no difference between bits and qubits. In fact, the difference is not in the possible answers, but in the possible questions. For normal bits, only a single measurement is permitted, meaning that only a single question can be asked: Is this bit a zero or a one? In contrast, a qubit is a system which can be asked many, many different questions, but to each question, only one of two answers can be given.
The way in which a one-qubit quantum computer is supposed to work, what happens when things go wrong? For a classical bit, the only thing that can go wrong is for a bit to unexpectedly flip from zero to one or one to zero. The same type of thing could happen to qubits, in the form of unexpected or unwanted rotations. But there's another type of process, one that researchers in quantum computing are constantly fighting to eliminate: decoherence. Decoherence happens when something outside of the quantum computer performs a measurement on a qubit, the result of which we never learn.
Pairs of qubits are much, much more than the sum of their parts.
Classical bits only become marginally more interesting when paired—it literally only makes the difference between counting to two and counting to four. Pairs of quantum bits, on the other hand, can be used to create entanglement. This phenomenon became one of the most controversial arguments in 20th century physics. It revolved around whether it could exist at all.
Not only can a single qubit take on a whole sphere full of values, it can only be measured along a single axis at a time. Not only that, but measuring, changes its state from whatever it was before the measurement to whatever states the measurement produced. That's a problem. In fact, it can be proven that even in principle it's not possible to copy an unknown qubit's state.
Consider the "singlet state," an example of an entangled two-qubit state. A singlet state has two defining characteristics:
Any single-qubit measurement performed on one half of the
singlet state will give a totally random result.
Any time the same single-qubit measurement is performed on
Both qubits in a singlet state, the two measurements will give opposite results.
To explain the characteristic we can say imagine if someone showed you a pair of coins, claiming that when both were flipped at the same time, one would always come up heads and one would always come up tails, but that which was which would be totally random. What if they claimed that this trick would work instantly, even if the coins were on opposite sides of the Universe. Yet time and time again, experiment after experiment, the results show that something about local realism must be wrong. Either the events simply cannot be predicted, even in principle, or there is something fundamentally nonlocal about entanglement—an ever-present bond between entangled particles which persists across any distance.
To give you an idea, consider that single-qubit states can be represented by a point inside a sphere in 3-dimensional space. Two qubit states, in comparison, need to be represented as a point in 15 dimensional space.
It's no wonder, therefore, that quantum physicists talk about a 100-qubit quantum computer like it's the holy grail. It's simply much too complicated for us to simulate using even the largest conceivable classical computers.
If we want to measure the polarization of a photon, So I put it through a polarizer. What that polarizer actually does is couple a polarization qubit to a spatial qubit, resulting in a superposition of two possible realities.That superposition is an entangled state. Using a different polarizer, it would be straightforward to unentangle it without ever making a measurement, effectively erasing the fact that the first measurement ever happened at all. Instead, a photodetector is placed in the path of the transmitted half of the entangled state. If there is a photon there, it will excite an electron. That excited electron will cause an electron avalanche, which will cause a current to surge in a wire, which will be sent to a classical computer, which will change the data in that computer's RAM, which will then finally be viewed by you.
That equation means every part of the experiment, even the experimenter, are all part of a single quantum superposition. Naturally, you might imagine that at some point, something breaks the superposition, sending the state irreversibly down one path or the other. The problem is that every time we've followed the chain of larger and larger entangled states, they always appear to be in a superposition, in this psuedo-magical state where any set of axes are equally valid, and every operation is reversible.
Maybe, at some point, it all gets too big, and new physics happens. In other words, something beyond quantum mechanics stops the chain of larger and larger entangled states, and this new physics gives rise to our largely classical world. Many physicists think that this happens, many physicists, think it doesn't, and instead imagine the universe as an unfathomably complex, inescapably beautiful symphony of possibilities, each superposed reality endlessly pulsing in time to its own energy.
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In 20 years we can combined all our communication system cell phones , computers , TV, radio and internet into chips on a thin headband that transmit information between the internet and our brain and also to others headband. That connection can lead us to have network enabled telepathy we will communicate directly to another person headband in the other part of the world, using just our thoughts.
Recognizing thoughts instead of voice speak can be seen as difficult but with training thought-talking could become easy and routine.
Your computer driven auto-drive electric car rolls its top down on this warm day. You manually drive to the electronic roadway on-ramp and relinquish the wheel. Your headband selects a video to enjoy on the way to the airport where your smart car drops you off at the terminal, then auto-parks itself. An intelligent cam scans your mind and quickly approves you; no waiting for ticket-check or security. While boarding the plane, you see a familiar face. Your headband immediately flashes his identity data and displays it on your eyes. Our headband enables us to speak or think of any question and get an immediate answer.
Considering this, will help a lot of people, because the necessity to learn languages for example would disappear, and the headbands will be available for everyone.
We can say quantum computers will greatly improve relationship, no more forgetting names and details plus increasing intimacy generated by communicating by thoughts could bring people around the world closer together.
With our headbands we will speak or think any question and get an immediate answer,
We still have some significant research and development ahead of us as we currently still are confronted with an unacceptably large amount of data to be processed simultaneously due to the lack of data present in the processor at the moment of calculation.
Even then, the answer obtained must be the most certain to the dimensional time where had been done the question.
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software ability of QuantumComputers & etc.)
