Introduction and Beginners Guide to Quantum Computing

Introduction

The quantum computers are similar to classic computers that are built in the year 1950s which has hardware’s, algorithms, Operating System with associated complier, high level languages and algorithms. The code is written in low level assembly language. Many companies have invested in the research on quantum computing viz Google, IBM, Amazon, DARPA, Honeywell (Alvarez-Rodriguez et al., 2016) (Hu et al., 2016) etc. The processing speed of the computer depends on the number of transistors that exists in the CPU. It is well-known that the computers process the inputs as binary values either zero or one. The transistors act as a switch and sends the input signals as zero or one. Gordon Moore cofounder of Intel quoted that “the transistor in CPU or the overall processing power doubles every two years”. The prediction came true from 1965 to 2013 i.e., the transistor (Vermersch et al., 2016) (Brecht et al., 2016) (Monz et al., 2016) capacity doubled every 18 months. But after 2013th the process started slowing down. So, more transistors needed to be incorporated. To place a transistor in the Integrated Circuits (IC) the size has to reduced and the method is followed till the year 2012. In 2013 the attempt was made to increase the speed by reducing the transistor size to the size of the atom but it led to the problem which is referred to as quantum tunneling. Quantum tunneling is the stage of the transistor that conducts the electron even in OFF state. Hence the concept of quantum computing arose to solve quantum tunneling (Veldhorst et al., 2014). The quantum physics and quantum mechanics concepts are used to develop the quantum computers. The quantum mechanics is the most fascinating concept. It works on the basis of “reality is stranger than fiction”.

Quantum supremacy: The processing speed of the quantum computing processor is represented as 2n where n represents the number of electrons. The quantum computer thus calculates 220 =10,48,576 operations per time. Google has also developed a quantum computer and claimed they have achieved the quantum supremacy. It generated random numbers one million times in the processing speed of 200 seconds. The Google researchers and engineers are responsible for this huge success. The invented quantum computing chip was named as sycamore. It works with 54 qubits (Albrecht et al., 2016). Each qubit ranges in the size of 0.22 millimeter in width. The main challenge maintains the qubit in proper climatic and vibration less environment else it will be prone to error. So, google placed the sycamore in a very lowest temperature of 15 milli kelvin which is 200 times lesser than the normal temperature.

Also, the sycamore is also protected from the outer vibrations. The Google CEO Sundhar Pichai also addressed that they have achieved the quantum supremacy and assures their achievement will be applied to various fields in the future. The problem which can’t be solved by the normal computer is hence proved to be solved by the quantum computer in an optimal time. Then the question “Will quantum computer replace our regular normal computers?” arises. But it is clear that due to the maintenance of the quantum computers it can’t replace the normal computers rather shall be used for various other applications. The real-time applications need millions of qubits. Since the maintenance of qubits are more expensive it is suspected to be prone to more errors when replaced instead of classical computers. Hence concluded that the problems that can be solved by classical computers are called as intractable problems and the quantum computers solves them in seconds.

The content is organized as follows: Firstly, section 2 explains the very short introduction about the ideas of building the quantum computer utilizing the functionalities of the quantum gates namely single qubit and multiple qubit gates. Secondly, the section 3 portrays the strength of quantum computers along with its properties. Then section 4 gives the dimensions of quantum computing. Finally the conclusion is in section 5.

1. Building Quantum Computer

The quantum information(Grilo & Kerenidis, 2017) (Sarma et al., 2015) is passed to the quantum computer using the quantum circuit which comprises of physically connected wires and quantum gates. Single qubit gates, multiple qubit gates and many other gates are used. As an introduction the above mentioned two gates are explained.