Quantum Computing

The advent of computers led to the digital age where many tasks that required a lot of manpower and several days to complete were processed by a computer in a few minutes or even seconds. The first computer models used to be huge in size, heavy, and consumed a lot of energy. These machines were not only slow but cumbersome to use. Only a few institutions and agencies were able to buy and use them since the cost of maintenance was high.
The advancement in silicon technology led to smaller computers from the early 1990s. Computers became cheaper and most people could afford their own personal computers. Nowadays, even smartphones and tablets have a higher processing power than the first computers and they can run complex graphics and algorithms. However, of all the computer types, supercomputers and mainframes have played a very big role in networking, banking, research, and data centers.
Conventional mainframes are getting overwhelmed by the increasing number of people who are connected to the internet. This problem is evident in top social networks and search engines that serve millions of users in a day. This has made man to think of a new type of computer – a machine which can process an unlimited number of complex tasks and serve hundreds of thousands of users without any significant reduction in speed.
Today, scientists are talking about a new kind of computer – a quantum computer. This type of computer is no longer a theory since several governments including the U.S and Britain have already pumped millions of dollars in the research and development of the first models. This machine will be a technological breakthrough in human history since it will enable people to perform complex mathematical operations, advanced simulations and complex research. It is expected to be faster than any computer ever built by man. Some people speculate that it might have a processing power of dozens of modern-day mainframes but it is hard to tell.
What is a quantum computer?
A quantum computer can loosely be defined as a computer machine that uses quantum mechanics to manipulate subatomic particles to achieve a massive processing power. The machine runs complex quantum algorithms that calculate the number and state of various subatomic particles in a split second. The computer can store 1s, 0s or even multiple numbers at the same time.
Unlike modern-day pc which process instructions in sequence, a quantum computer can process various workloads in parallel. Once the processing is complete, it measures the subatomic particles to determine the state of the outcome. This technique makes a quantum computer several million times faster than modern-day PCs.
How does it work?
Unlike conventional computers that process and manipulate binary digits, this one will be able to generate qubits (quantum bits). qubits are simply subatomic particles. Electrons and photons are the major subatomic particles undergoing research. Scientists and engineers are trying to come up with a way to safely generate and manipulate these particles since they are unstable.
The computer has to generate and maintain the state of the particles to store data. The computer processes the information by knocking the desired particles into other states to process information. Algorithms determine the state of resulting particles after the operation is complete to output results. The most common ways of changing and containing the subatomic particles are the use of laser beams, radio waves and even electromagnetic fields.
Qubits can be made using quantum dotes which are simply small semiconductors which contain holes, electrons and charge carriers. Qubits can also be made using ion traps. This involves removing or adding electrons in an atom which creates an ion. This ion is held in place using a laser beam which can also flip the ion into various states. Another way to make Qubits is to create photons or other subatomic particles inside optical cavities.
Qubits are faster than binary bits since they possess the two main quantum properties namely: entanglement and superposition. Superposition is the ability of these subatomic particles to represent multiple 0s and 1s at the same time. This enables the computer to process several instructions using the same qubits at the same time.
On the other hand, entanglement involves generating several pairs of qubits with the same state – it can be 1 or 0. If the state of one qubit changes, the other one also changes instantly even if the two particles are far away from each other. This property is advantageous in that it exponentially increases the processing power if more qubits are added to the machine. This is quite different from conventional computers whose processing power is limited to the number of binary bits it can handle at a time.
Major Challenges in developing a quantum computer
Quantum computing is a new field and there is no standard method of isolating and manipulating qubits. For this reason, almost every researcher is trying to come up with a new way to control qubits and this consumes a lot of resources and time.
Furthermore, the use of qubits in computing is still error-prone at the moment due to decoherence. Decoherence simply means the way the sub-atomic particles decay and disappear quickly. Quantum noise such as the slightest changes in temperature and vibrations affect the fragile qubits thus causing computational errors.
Researchers are trying to come up with new ways to protect these particles from “noise” to reduce errors but they still have a long way to go. At the moment, some companies are using vacuum chambers while others are using supercooled fridges to try to stabilize the state of qubits.
Fortunately, some scientists are trying to develop smart quantum algorithms that will be able to detect possible errors in real-time and correct them simultaneously. In addition, studies indicate that thousands of qubits can be used to create a logical qubit which is not only powerful but also reliable.
Quantum computers have a massive number-crunching ability hence they can process complex instructions in a shorter period of time. Having said that, these machines might not phase out conventional personal computers in the near future since it will be a waste of processing power. The modern-day personal computer already has enough processing power needed by most standard uses. However, quantum computers will be helpful in carrying out advanced medical and technological research. However, it might take a few more years for humans to start using this machine since qubits are difficult to generate and manage.

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