Quantum computing | Why Need | How does Quantum Computers Work?

What is Quantum computing?

Quantum computing is a rapidly growing technology that uses the laws of quantum mechanics to solve complex problems that are not easy for supercomputers.

But why do we need Quantum Computers?

There are some problems for which even supercomputers are not enough. When engineers faced challenging difficulties in solving some issues, they used supercomputers. Supercomputers are large traditional computers with thousands of more GPU and CPU than a conventional computer. Even with these features, they also lack in solving some problems.

Supercomputers can do any traditional task, and they are efficient machines for performing some complex operations. The only thing that can be stuck even on a supercomputer is complexity. If a supercomputer is given a task with a higher degree of complexity than the traditional one, it fails too.

A complex problem in which even supercomputers can be stuck in those problems involves multiple variables’ interaction. Modelling the behavior of individual atoms in a molecule is a complex problem because of all the different electrons interacting with one another. Sorting out the ideal routes for a few hundred tankers in a global shipping network is complicated too.

Why are Quantum Computers Faster?

A supercomputer can perform complex tasks like sorting in an extensive database. But it can struggle to see the patterns in that data which determine how it behaves.

For example, an extensive database of proteins, which are strings of amino acids, become useful biological machines when folded into complex shapes. Figure out how these proteins will fold is the problem, and the solutions to these problems are necessary implications of biology and medicine.

A traditional supercomputer will try to fold a protein with a brute force approach and use its multi-processing capability to check every possible way of bending the chemical chain before arriving at an answer.

But the supercomputer stalls as the protein sequences get longer and more complex. Theoretically, a chain of 100 amino acids can fold in any one of many trillions. Still, no computer has the memory to handle all the possible combinations of every fold of the protein.

Quantum algorithms use a new approach to these complex problems by creating a multidimensional space where the patterns that link individual data points emerge. In the case of a protein folding problem, this pattern may be the combination of folds required to produce the least energy, and that combination of protein folds will be o solve the problem.

Classical computers are not capable of creating computational spaces, so thus they are also not capable of finding these patterns. In the case of proteins, some early quantum algorithms can discover folding patterns in a new efficient way without the complicated checking procedures of traditional computers as quantum hardware scales. These algorithms are more advanced so that they can tackle complex protein folding problems too complex for any supercomputer.

How do quantum computers work?

Quantum computers are more minor intelligent machines requiring less energy than supercomputers. An IBM Quantum processor is a wafer not much bigger than the one found in a laptop. And a quantum hardware system is about the size of a car, made up mostly of cooling methods to keep the superconducting processor at its ultra-cold operational temperature.

A classical processor uses bits to perform operations, and a quantum computer uses quantum bits to run multidimensional quantum algorithms.

Superfluids

Your desktop computer likely uses a fan to get cold enough to work, and our quantum processors must be very cold – about a hundredth degree above absolute zero. To achieve this, we use super-cooled superfluids to create superconductors.

Superconductors

At shallow temperatures, some materials in processors exhibit another significant quantum mechanical effect in which electrons move through them without any resistance, which makes them superconductors and when electrons pass through superconductors, they match up to form cooper pairs which can carry a charge across barriers, or insulators, through a process known as quantum tunnelling—two superconductors placed on either side of an insulator form a Josephson junction.

Control

For superconducting quantum bits, quantum computers use Josephson junctions. By firing microwave photons at these quantum bits, we can control their behaviour and make them hold, change, and read out individual units of quantum information.

Superposition

A quantum bit itself is not helpful. But it can perform an essential trick by placing the quantum information into a state, representing a combination of all possible configurations of the quantum bit. Groups of quantum bits in superposition can create complex, multidimensional computational spaces, and complex problems can be described in new ways in these spaces.

Entanglement

It is a quantum mechanical effect that correlates the behavior of two different objects. When two quantum bits are entangled, changes to one qubit directly impact the other, and quantum algorithms use these relations to find solutions to complex problems.