Context
- Recently, three scientists – Frenchman Alain Aspect, American John F Clauser, and Austrian Anton Zeilinger – were awarded the 2022 Nobel Prize in Physics for their work on quantum information science, a field with numerous applications, including encryption.
- They discovered how unseen particles, such as photons, can be linked or entangled with each other even when separated by great distances, a field that alarmed Albert Einstein, who described it as “spooky action at a distance” in a letter.
Relevance:
GS-3: Science and Technology- developments and their applications and effects in everyday life.
Mains Question
What exactly is Quantum Technology? Discuss its potential applications as well as the importance of the ‘National Mission on Quantum Technologies and Applications’ in this regard. (150 Words)
Quantum technology:
- Two objects cannot occupy the same space at the same time, according to classical physics (based on Newtonian mechanics)
- It was thought until the early twentieth century that this was a fundamental physics law that was followed by everything in nature
- However, scientists began to look into particles like atoms, electrons, and light waves that did not appear to follow these laws.
- The subject of quantum mechanics was founded by Max Planck, Neils Bohr, and Albert Einstein in an attempt to investigate the “quirky” principles that did bind such particles.
About:
- It is a type of technology (developed in the early twentieth century) that operates on the principles of quantum mechanics – the physics of subatomic particles, such as quantum entanglement and quantum superposition.
- As a result, it is based on phenomena exhibited by microscopic particles (such as photons, electrons, atoms, and so on) that differ significantly from how normal macroscopic objects behave.
The underlying principles of quantum technology are as follows:
- Quantum entanglement (QE):
- Quantum entanglement occurs when two atoms are connected or entangled despite their separation
- If one atom’s properties change, the other changes instantly, and quantum mechanics observe these changes in properties.
- It improves communication security by using quantum-protected encrypted keys, and entangled atoms can be used to detect whether data transmission has been compromised.
- Quantum entanglement:
- Quantum superposition is the theory that subatomic particles can exist in multiple states at the same time.
- Quantum computers are a practical application of this principle.
- Whereas digital computers store data as bits (binary of 0 and 1), quantum computers use qubits, which can be either a 1 or a 0 at the same time.
- This superposition generates a nearly infinite set of options, allowing for extremely fast calculations.
Applications:
- Quantum technology promises to improve a wide range of everyday devices, including:
- Improved navigation and timing systems.
- Improved communication security.
- Improved healthcare imaging through quantum sensing (using quantum phenomenon to perform a measurement of a physical quantity).
- Quantum computers provide more powerful computing.
- Improved disaster management through better prediction, computing, and so on.
- To comprehend biological phenomena such as smell and consciousness, as well as the spread of pandemics such as Covid-19, etc.
Nobel Prize-winning scientist’s work:
- Quantum mechanics allows two or more particles to be entangled, resulting in particle coordination. This was initially thought to be due to hidden variables.
- However, in the 1960s, John Stewart Bell discovered that there are no hidden variables at work. When measuring the properties of one of the particles, coordination between entangled particles is a matter of chance
- Bell established a mathematical inequality stating that “if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value.”
- However, quantum mechanics shows that this value can be exceeded, resulting in a stronger correlation between the results than is possible when hidden variables are used.
- Exceeding this figure proves that there is no mysterious “spooky action” and that the universe is governed by quantum mechanics.
Concerning this year’s work:
- This year’s Nobel laureates have built on Bell’s work over several decades.
- To test Bell’s inequality, American physicist John Clauser devised a realistic experiment that involved passing entangled photons through polarisation filters (commonly used in sunglasses to block light at specific angles).
- His experiments demonstrated a clear violation of Bell’s inequality, confirming that no hidden variables were at work.
- Clauser’s experiment, on the other hand, had limitations in that the settings for detecting entangled photons were fixed, which meant that the experimental setup itself might have been unable to detect some particles controlled by hidden factors.
- Alain Aspect, a French physicist, attempted to design an experiment that eliminated this potential bias by changing the measurement settings only after the entangled photons had left their source, ensuring that the setup had no effect on the results.
- Austrian physicist Anton Zeilinger was among the first to investigate quantum systems with more than two entangled particles, which now serve as the foundation for quantum computation and allow entangled particles to be manipulated.
- One of his most well-known achievements was the discovery of quantum teleportation, which allows particles to acquire previously unknown quantum properties from other particles over long distances.
Significance:
- The development of transistors and lasers resulted from the first quantum revolution.
- The ability to handle and manipulate entangled particle systems will provide researchers with better tools to build quantum computers, improve measurements, build quantum networks, and establish secure quantum encrypted communication.
- Quantum computers can perform complex calculations that are far beyond the capabilities of traditional computers.
- Quantum computing has already demonstrated promise in chemical and biological engineering, as well as in cybersecurity.
- Computing systems capable of managing massive datasets and running complex simulations will also help areas such as artificial intelligence and Big Data.
