Science & Tech, World

A Primer on Quantum Computers

Quantum computers uses atoms and molecules to perform memory and processing jobs. These atoms are assembled into Qubits that are monitored to complete the processes. These machines have the potential to perform drastically faster than current silicon based computers.

Currently, scientists have built quantum computers that can perform particular calculations, but we’re still far from being able to replace current computers.

How do Quantum Computers Work?

All computers are based on the Turing machine. This machine is a theoretical device that has a tape of unlimited length that is divided into squares. Each of these squares can contain a 1, a 0, or be left blank. A read-write machine reads these squares. This results in the instructions that tell the machine what program to run and how. A Quantum Turing machine has a tape and read-write device that exist in quantum state. This means that the tape is filled with 0s, 1s, a combination of the two, and any value in between, all at the same time. This allows the quantum machine to perform multiple calculations at once.

Quantum computers are not limited to two states as standard computers are, instead they function by encoding qubits. Qubits are atoms, ions, photons or electrons that act together to form the memory and processor of the computer. Because of the ability of the quantum computer to contain the qubits that are in multiple states, these machines would be able to function millions of times better than current computers.

The behavior of the Qubits is where the quantum computer gets its power. The multiple states that can be held by qubits at the same time allows the computer to exhibit parallelism and process millions of procedures at once instead of the one that is processed by a typical PC.

Qubit States and Entanglement

Quantum computers are also dependent on the mechanic called entanglement. When observing the atomic particles in a qubit you force them to choose a state and this causes them to behave as a typical computer instead of as a quantum computer. Because of this, the state of these qubits must be measured indirectly so that the state of the qubits is not affected.

Entanglement states that a force applied to two atoms can cause them to be entangled. The second atom will then take on the properties of the first. When undisturbed, an atom will spin in every direction. Once it is disturbed it chooses one spin or value. While this atom chooses a spin, the entangled atom will be forced to choose the opposite spin or value. This entanglement theory enables scientists to decipher the value of a qubit without looking at it directly.

Qubits are controlled by scientist using control devices. These include ion traps, optical traps, quantum dots, semiconductor impurities, and superconducting circuits. These controls are still under development, as advances are made to each of these the qubits become easier to control.

Who Produces Quantum Computers?

Much of the research and technology required to make quantum computers a practical reality is still theoretical. Because of this, much of the work being done on these computers is done in research labs and facilities. In 1998 Los Alamos and MIT made advancements studying the use of the entanglement theory to analyze interactions between states as a way to monitor the state of the qubits. In 2000 scientists developed a 7-qubit quantum computer that existed within a single drop of liquid. In this case a nuclear magnetic resonance was used to manipulate the atomic particles. The IBM-Almaden Research Center also developed a quantum computer in which the qubits were programmed by radio frequency. The Qubits were monitored by a nuclear magnetic resonance instrument. This computer was able to solve a mathematical problem in one step that would take a standard computer multiple cycles.

In 2005 the Institute of Quantum Optics and Quantum Information at the University of Innsbruck created the first qubyte. This is a series of 8 qubits. It was developed using ion traps. Since then, other scientists have developed methods to control quantum particles on a 12-qubit system, this had previously been limited to 8. A startup company has also claimed to have a functioning 16-qubit system that could solve Sudoku and other pattern problems but many are skeptical about the validity of their process and the machine.

Who Works with Quantum Computers?

Computer scientists are currently the ones primarily working with quantum computers. Many believe that the technology needed to create a practical and functional quantum computer has not been developed yet. As this technology advances, stronger and more functional quantum machines will be able to be produced and used to process more complex problems.

As technology continues to develop, the power of quantum computers will continue to grow. Eventually these machines will be able to process complex problems significantly faster than regular computers. In addition to this, these machines will be able to process multiple problems at once. Development is limited by the ability of scientists to control the qubits. These qubits hold the data and function as the memory and processor for the quantum computer. Once the scientists can more easily control larger numbers of qubits the computers will become stronger and more practical for everyday applications. Advances in techniques to read the state of the qubits without affecting them, which is currently done with the nuclear magnetic resonance instruments, will also allow these computers to be more widely studied and applied.