Quantum computing (QC) is a rapidly emerging technology that harnesses the unique behaviour of quantum mechanics to perform calculations exponentially faster than classical computers. Superposition and entanglement are the two principles of quantum physics that underpin quantum computing.
A quantum system’s capacity to exist in numerous states simultaneously is known as superposition. Entanglement refers to the capacity of coexistence of two states (qubits) in a single quantum state. Both of these characteristics enable quantum computers to do functions that are beyond the capabilities of traditional computers while using less energy.
The disciplines of computer science and quantum physics have long had their own separate academic cultures. The fields of quantum mechanics and computer science started to merge when physicists used quantum mechanical models to solve computational issues and swapped digital bits for qubits. The quantum turing machine, which makes use of quantum theory to describe a condensed computer, was first proposed by Paul Benioff in 1980. Small-scale quantum computers are constructed utilising superconductors and trapped ions. The viability of the technology was first proven in 1998 by a two-qubit quantum computer. Subsequent studies have increased the number of qubits and decreased error rates. Using a 54-qubit machine, Google AI and NASA declared in 2019 that they had achieved quantum supremacy and completed a computation that was impractical for conventional computers. (Though the validation of their claim is under review).
The paradigms of quantum computing and classical computing are essentially distinct and operate according to different principles. Some of the major differences are:
1. Speed: Quantum computing is significantly quicker than classical computation. The processor’s speed of classical computing is constrained by the clock rate and transistor speed whereas, the quantum parallelism phenomenon enhances exponentially the speed of quantum computing.
2. Capability: The calculation capabilities of quantum computing are far more than classical computing. Quantum computing, for example, can factor large numbers quicker than traditional computation.
3. Error rate: Quantum computing has a higher error rate than classical computing as qubits are prone to being entangled by other particles. Error-correcting mechanisms in quantum computers must be more complicated than those in traditional computing.
4. Infrastructure and software: In comparison to traditional computing, quantum computing is still in its early phases of development. Quantum computing infrastructure and software tools are actively being developed. Classical computing, on the other hand, already has an established infrastructure and several well-known programming languages.
Though quantum computing is a relatively new topic, it has the potential to influence results in a wide range of companies and scientific fields. Here are a few examples of practical quantum computing applications that we might see in the future:
Finance: Portfolio optimization, risk management and asset pricing are some of the areas that can greatly benefit from the advent of Quantum computing.
Healthcare Industry: Quantum computing can generate a new era in the healthcare industry. It has the potential to enable significant advances in the discovery of life-saving drugs, rapid DNA sequencing, early illness detection, and other compute-intensive healthcare-related tasks that have yet to be thoroughly explored.
Artificial Intelligence (AI): Quantum computing can completely recolonize the field of AI by providing the basis for solving some of the most challenging problems in artificial intelligence.
Travel and Transportation: Quantum computing can help with travel and transportation in a variety of ways, including upgrading signals, controlling air traffic, determining the optimal traffic routes, and much more.
Quantum computing has the potential to transform many other industries, including supply chain and logistics, consumer goods, quality control and maintenance, product design and testing in process industries, and so on.
Quantum computing has immense potential for development and problem-solving in a wide range of industries. However, it has its limitations.
Decoherence or Decay: The slightest disturbance in the qubit environment can cause decoherence or decay resulting in the collapse of computations or errors.

KEY TAKEAWAYS

QC involves phenomena in quantum physics (qubits) to create new ways of computing.
Conventional computer are unidimensional i.e. it can be either 0 or 1, a qubit can exist in a multidimensional state.
The power of QC grows exponentially with more qubits.
The power of classical computers grows linearly more bits.

Low Precision: They have a low level of precision as scientists have to create their own qubits, which is hard to control, resulting in malfunction or constant shut down of the system.
Error correction: Error correction has not been perfected making its computational potentially unreliable.
Not Viable: Lack of qubits prevents quantum computers from living up to their potential for impactful use. Researchers have yet to produce more than 128.
According to global energy leader Iberdola: “Quantum computers must have almost no atmospheric pressure, an ambient temperature close to absolute zero (-273°C) and insulation from the earth’s magnetic field to prevent the atoms from moving, colliding with each other, or interacting with the environment.”
“In addition, these systems only operate for very short intervals of time, so that the information becomes damaged and cannot be stored, making it even more difficult to recover the data”.
India and Quantum Computing
One of the key initiatives of the Indian government is the “Quantum Computing Applications Lab (QCAL)”, which was launched by the Ministry of Electronics and Information Technology (MeitY) in collaboration with Amazon Web Services (AWS). QCAL intends to expedite the use of quantum computing in India by offering access to quantum computers, tools, and resources to researchers and developers.
The Central Government has set out Rs. 8000 crores ($ 1.2 billion) for the “National Mission on Quantum Technology and Applications (NMQTA)” in the Union Budget for 2020-2021 and will be implemented by the Department of Science and Technology. Under the Prime Minister’s Science and Technology Innovation Advisory Council (PM-STIAC). Quantum Technologies and Applications is one of 9 missions of national importance. The program contributes to scientific research for India’s sustainable development through the office of the principal scientific advisor. The goal is to create a strong quantum technology ecosystem in India.
The future of quantum computing is bright, it has the potential to tackle some of humanity’s most difficult issues faster, efficiently, and accurately. India is also taking significant steps towards establishing itself as a leading player in the global quantum computing industry. With the right support and investment, India has the potential to become a major hub for quantum computing research and development.

LATEST IN INDIA

On March 27-28, 2023, the First International Quantum Communication Conclave was held in New Delhi. Telecom Minister Ashwini Vaishnaw launched India’s first quantum computing-based telecom network link between Sanchar Bhawan and National Informatics Centre office in New Delhi. He also announced prize money of Rs 10 lakh for ethical hackers who can break the encryption of the system and also launched a hackathon challenge for anyone who can break the system with a reward of Rs 10 lakh per break.

Key points of National Mission on Quantum Technology and Applications

The Mission focuses on fundamental science, translation, technological development, and natural property fulfilment.
The mission can aid in the creation of next-generation skilled labour, translational research, and entrepreneurial and start-up ecosystems.
Quantum principles will be applied to solve extremely complex problems related to computing, communications, sensing, chemistry, encryption, imaging, and mechanics.
Their applications will be expanded to encompass aerospace engineering, numerical weather forecasting, simulations, safeguarding communications and financial transactions, cybersecurity, advanced manufacturing, health, agriculture, and education.
It will place India among the few countries with an advantage in this growing field, giving it a stronger advantage in achieving multifold economic growth and an authoritative leadership role.