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Editorial Articles


Issue no 08, 20- 26 May 2023

Taking a Giant Leap to the Future National Quantum Mission

TV Venkateswaran

The past has encompassed eras of stone, bronze, steel, and concrete, while we currently find ourselves in the silicon age. Looking forward, the future holds promise for the quantum age. Recently, the cabinet's approval of the 'National Quantum Mission (NQM)' has granted India access to the exclusive club of nations venturing into the realm of cutting-edge Quantum Technologies (QT). This technology holds immense potential in solving problems related to computation, secure communication, sensing and metrology, personal medicine, and imaging. With a generous allocation of Rs 6003.65 crores over the next six years, India's burgeoning efforts in research and development of Quantum Technology Applications (QTA), are poised to make significant strides and propel the nation towards new heights.

In a recent article, Shri Jitendra Singh, Minister of Science and Technology, Atomic Energy, and Space, stated that with the announcement of the National Quantum Mission, India has secured a place on the global quantum map. Furthermore, he expressed that the quantum mission will bring India a step closer towards achieving quantum readiness and consequently, leadership in the future.

What is Quantum Mechanics?

Classical physics is the branch of physics that was developed by Newton and his contemporaries. According to classical physics, when a bat hits a ball, the ball moves in a parabolic path, while striking a carom causes the coin to move straight and bounce off the edge of the board, changing the trajectory. The Moon orbits the Earth in an elliptical path, and it is possible to locate it at any given point in its orbit. In contrast, a wave is not localised. When a stone is dropped into a still lake, ripples spread outwards. Waves oscillate and wiggle and do not bounce off each other when they collide, but rather interfere with one another. When two waves collide, the crest may meet the crest, resulting in a double wave, or the crest may meet the trough, leading to constructive and destructive interference. All of these motions are well-described by Newtonian physics. Within this framework, a moving ball, coin, or the Moon follows a definite path and occupies a specific point in space with a definite velocity. A ball moves like a 'particle', but light or radio waves behave like a wave. As scientists delved into the microcosmos, they found that the behaviour of atoms, electrons, and photons was peculiar. While a fast-moving electron behaved like a particle, a slow-moving electron behaved like a wave. Under different circumstances, atoms, electrons, and photons exhibited both particle-like and wave-like behaviour. Classical concepts such as well-defined paths, precise position, and momentum were no longer applicable in the realm of atoms and sub-atomic particles. In the early 20th century, physicists such as Planck, Niels Bohr, Max Planck, Einstein, SN Bose, and Heisenberg developed a new law to explain this strange behaviour, which is known as quantum mechanics. Two of the most bizarre quantum behaviours are entanglement and superposition.

What is Quantum Entanglement?

Suppose we toss a coin two times. Let's say the first time it landed on heads (H). From this information, we cannot determine the outcome of the second toss. It could be heads or tails (T). Scientists say that the results of each toss are 'independent'. Now, let's consider the case of a pair of gloves. If we find one to be the right hand, we can immediately conclude that the other is the left hand. This means that the pair of gloves are entangled. Similarly, just as two swords cannot fit into the same sheath, two electrons cannot occupy the same energy level. However, in the helium atom, two electrons are in the first orbital. This is possible because of the quantum property called the spin of these electrons, which is opposite to each other. Therefore, if we determine the spin of one electron, we can immediately determine the spin of the other, as both are entangled. Sometimes when a pair of electrons is released in opposite directions during a reaction, they have entangled spins. By measuring the spin of one electron, we can determine the spin of the other, even if that electron is at the other end of the universe.

 

What is Quantum Superposition?

Schrödinger constructed an imaginary experiment to illustrate the idea of 'Superposition' in Quantum Mechanics. Imagine placing a cat in a sealed box with a tiny bit of radioactive material inside. When the radioactive material decays, it triggers a Geiger counter, which then releases poison, ultimately killing the cat. Thus, if there was no radioactive decay, the cat remains alive, and if there was radioactive decay, the cat dies. However, as radioactive decay is a random process, there is no way of telling which specific radioactive atom will decay in which time interval. Therefore, unless we open the box and observe, we cannot know if the cat is alive or dead. We can say that the cat was in a superposition, which is a mixture of the states of being alive and dead. This is similar to several waves with mixed frequencies superposed to create an ensemble of musical tones. Similarly, a quantum superposition is a linear combination of other distinct quantum states. Thus superposition itself can become a new state. However, when a measurement is done, various potential forms collapse into one state that is measured.

 

What is Quantum Technology?

Quantum technologies are developed using the principles of quantum mechanics, such as superposition and entanglement. However, even gadgets already in use today, such as the laser (Light Amplification by Stimulated Emission of Radiation) and the tunnelling electron microscope, work on the principles of quantum mechanics. Nonetheless, second-generation quantum technologies are emerging fields in physics and engineering that employ or harness quantum mechanical effects for their operation. For instance, when microelectronics are miniaturised to the sub-10-nanometer (nm) level, quirky quantum effects, such as the wave nature of particles, materialise. Quantum devices use explicitly quantum properties, such as spin, for their operation. Like the zero and one, the two values of the spin could be used to store a bit in a quantum memory device. Some major domains of quantum technologies include Quantum Communication, Quantum Cryptography Quantum Computation, Quantum Sensing & Metrology and Quantum Materials.

 

What is Quantum Communication?

Another line of development is quantum-safe cryptography, which aims to make encryption safe from brute force attacks. For example, let's say there's a three-number lock safe, and one has to try a maximum of 1000 options to find the proper sequence of three numbers. With one try per second, we can crack the lock open in under 17 minutes. If the lock has four-number sequences, there are 10,000 unique sequences possible. While a fourdigit lock is more secure than a three-digit one, it can still be cracked by brute force in less than three hours. In contrast, the 128-bit Advanced Encryption makes it highly challenging to crack. Even with the fastest computer, it would take nearly 50,000 core years to try all the possibilities. Quantum-safe cryptography is focused on developing mathematical problems that are exhaustive even for a quantum computer

What are Quantum Computers?

Computers store, display and perform operations on zeros and ones, called bits. Quantum computers use what are known as qubits -quantum bits. Unlike the conventional bits, a series of 0s and 1s, the qubit can take on values of not only zeros and ones and, due to the weird superposition, a combination of both simultaneously. This makes the quantum computers store a mammoth amount of data and compute multiple calculations simultaneously than even state-of-the-art supercomputers. In conventional computers, physically, the bits are a transistor in a RAM cell or a cell in a Solid State Drive (SSD). For example, in a 1 GB flash drive, there are little more than 8 billion transistors. Zero is set by charging the floating gate of the transistor, and a 'one' is denoted by removing the charge. In quantum computers, researchers are trying several quantum properties such as the spin of quantum particles, energy levels of electrons in neutral atoms or ions, the polarisation of photons, and the direction that the current flows around an electrical circuit made of superconducting material at low temperatures are used as the physical means to store qubits.

 

What are Quantum Sensors?

Using quantum properties such as quantum coherence, interference, and entanglement researchers are developing novel sensors that can detect tiny changes in motion, electric & magnetic fields, temperature, and light at atomic level resolution. Quantum Photonics Devices use tapered nanowires that turn the incoming photos into electric current that can be suitably amplified and detected. One can develop devices for night time surveillance, medical imaging and quantum radars using such sensors. When they are excited and current flows, the neuronal assemblies in the brain produce magnetic fields. We can do Magneto-Encephalography (MEG) brain imaging by measuring the magnetic fields. However, the catch is the magnetic field generated by the brain is only a billionth of the Earth's field, in the order of ~100fT. Sensors like the Superconducting Quantum Interference Device (SQUID), quantum enabled magnetic field sensors such as Optically Pumped Magnetometers (OPMs) can make it possible

 

What is a Quantum Material?

Often the sum is more than just the sum of its parts. Take bronze which is an alloy of copper with tin or arsenic. However, bronze is much harder than the components that go into making it. Likewise, when the Yttrium Barium Copper Oxide, with the acronym YBCO, is cooled to nearly minus 190 degrees, it becomes superconducting material. The current flows with zero resistance and can even last for many years. The exotic quantum effect emerges due to the Cooper-pairs of electrons in the supercooled lattice structure that starts exhibiting wave-like properties. This, for example, is a quantum material. Trivially all materials work on the principles of quantum mechanics. Yet, quantum effects, such as superposition, are more pronounced in some materials. The interactions of electrons at a quantum mechanical level provide exotic electronic, magnetic and optical properties. Quantum materials could be used to develop novel technocologies, including quantum computers, sensors, levitation, medical imaging and more vivid display devices. Take, for example, Quantum Dots (QDs). They are fabricated nanocrystals that reflect precise colour depending upon their size. When the blue light is shined, big ones glow in red and smaller ones in green. Liquid Crystal Displays (LCDs) made with quantum dots will provide much richer colours and sharper images and are highly energy efficient. QDs can be used in developing LCDs and for making next-gen solar cells that can milk solar energy radiated in several wavelengths.

 

Strides Made by India: The Raman Research Institute in Bengaluru is involved in experimental and theoretical investigations in quantum optics, which aims to use entangled photons, particles of light, to design and develop various quantum technologies. With the support of the ISRO Space Application Centre, a state-of-the-art Quantum Information and Computing (QuiC) laboratory is proposed to be set up at RRI to develop an indigenous, hackproof quantum communication in space. Recently, the Defence Research and Development Organisation (DRDO) and the Indian Institute of Technology (IIT) Delhi have joined hands to develop, test, and demonstrate quantum key distribution from Prayagraj to Vindhyachal in Uttar Pradesh, a distance of over 100 km. A centre for excellence in quantum technology has been established at the Indian Institute of Science, Bengaluru, which aims to bridge the gap in expertise and facilities for both theoretical and experimental exploration to make the Indian pursuit in this field on par with the rest of the world. Specific domains such as superconducting qubit devices, single photon sources and detectors for quantum communications, integrated photonic quantum networks, quantum sensors, quantum algorithms and simulations, and post-quantum cryptography will be the focus. TIFR has set up a Quantum Measurement and Control Laboratory (QuMaC) to develop a quantum bit (qubit) that can store and process information using superconducting circuits. Two of the energy levels of the nanofabricated electrical circuits that behave like an artificial atom can be used to develop quantum computing machines. Meanwhile, researchers at IIT Bombay are investigating the quantum magnets of migratory birds that use the electron spin as a compass to make a foray into quantum biology. For the past few years, the Indian Institutes of Science Education and Research (IISER) Pune and the Centre for Development of Advanced Computing (C-DAC) have been exploring quantum sensors and metrology and quantum computing and simulations. Recently, the 13 research groups from IISER Pune that work on the various aspects of quantum technology have been networked into a technology hub called I-Hub Quantum Technology Foundation (I-Hub QTF). The hub will incubate QT start-ups, develop industry and academia skill sets, conduct workshops to build expertise, run courses to grow human power, and develop stateof-the-art infrastructure for research in various areas of QT.

 

Mission: Assessing the forays made by Indian institutions, the Technology Information Forecasting and Assessment Council (TIFAC) DST drafted a 'Concept Note on National Mission on Quantum Technology & Applications (NM-QT).' The report pointed out that the lack of resources at the undergraduate and graduate levels limits the growth of the quantum-ready workforce, and university-level adoption is required to beef up manpower in R&D and compete on a global stage. Furthermore, it stated that technical infrastructure to advance quantum technologies needs to be established to give a flip to research and development in this area. Following these recommendations, the Government of India has announced the National Quantum Mission. The mission will enable India to scale up scientific and industrial R&D and create a vibrant and innovative ecosystem for accelerating Quantum Technology-led economic growth. India aims to leverage itself into a leading nation in QT. The major milestones of this mission are to build a quantum computer using superconducting and photonic technology with 50-1000 physical qubits, develop, design and demonstrate satellite-based quantum communication that enables secure, hack-free, inter-city quantum key distribution over 2000 km and establish a multi-node quantum network. As part of the mission goals, high-sensitivity magnetometers, precision Atomic Clocks, quantum materials such as superconductors, novel semiconductor structures and topological materials, and novel quantum devices such as single photon sources/detectors will be indigenously developed. To create an ecosystem for research and development, Thematic Hubs (T-Hubs) for focus areas, Quantum Computing, Quantum Communication, Quantum Sensing & Metrology, and Quantum Materials & Devices will be set up. [Interested readers can watch the popular science videos Quantum Science and Technology and 'Quantum Mission of India' produced by Vigyan Prasar and hosted by India Science TV]

 

(The author is Senior Scientist, Vigyan Prasar, Department of Science and Technology, New Delhi. He can be reached at tvv123@gmail.com)

Views expressed are personal.