Connect with us

Space & Physics

Superconducting Saga: What happened to LK-99?

The community of condensed matter physicists was put under spotlight in the wake of a paper, triggering a frenzy like none other in recent times.

Rutvij Gholap

Published

on

Image shows superconductor levitation; Source: Pongkaew / Wikimedia Commons

In July 2023, two South Korean experimental physicists, Lee Sukbae and Kim Ji-Hoon published a pre-print in arXiv, claiming discovery of superconductivity in a sample, occurring at room temperature.  

The condensed matter physics community was put under spotlight in the wake of this paper, triggering a frenzy like none other in recent times.

The material dubbed, LK-99, after the initials of the South Korean physicists, promised nothing short of a revolution to the electronics industry.

But before I go further, let’s go through some superconductivity basics.  

What are superconductors?

Basically, superconductivity is a macroscopic quantum phenomenon. Our story begins with two ground-breaking experiments.

In 1911, the Dutch physicist, Heike Onnes observed that a mercury wire dipped in liquid helium, offered zero resistance to the passage of electricity, when the temperature of the mercury was lowered to-269C.

In 1937, Pyotr Kapitsa, John F. Allen and Don Misener discovered that at an even lower temperature close to -273C, liquid helium-4 transformed into a superfluid. A superfluid’s an exotic fluid exhibiting zero viscosity.

Both these exotic phenomena of superfluidity and superconductivity are closely linked, though they’re not the same.

Heike Onnes; Source: Anefo / Wikimedia

However, this effect would go for years without a solid theory, until the physicists’ trio, John Bardeen, Leon Cooper and John Schrieffer, put together a ‘complete’ microscopic theory, known as the ‘BCS theory’. The theory makes a number of quantitative predictions about the behavior of superconductors. Most importantly, it shows how pairs of electrons would couple to form Cooper pairs, overcoming mutual repulsion below a set critical temperature. Bardeen, Cooper and Schrieffer would go on to win the 1972’s Nobel Prize in Physics for this work.

As much as superconductors revolutionized the electronics industry in the 20th century, the temperatures at which this effect is commonly seen is in the same regime as outer space. It takes resources for laboratories to reach these temperatures. But imagine if nature showed us a material that can become a superconductor at room temperature …

The case for ‘room temperature’ superconductors

But you may be wondering what’s the big deal with room temperature superconductors anyway? For one, they’re promising an overnight revolution of sorts in the electronics industry. The approximately 7% loss of energy there is to pass currents through wires during transportation, can be brought down to near zero with room temperature superconductors. Another important use of these superconductors would be in the development of strong magnetic fields. Strong stable magnetic fields are used in MRI imaging and maglev trains.

Source: Ramon Salinero / Unsplash

This could make such technologies more accessible and cheaper to the public. Renewable energy generation from solar and wind power could see their efficiency rise with the help of room-temperature superconductors. The use of room-temperature superconductors could grow exponentially more after its discovery, even in applications we do not know yet. Think of the world today without any semiconductors, it would be tough to live without our LED lamps or solar panels. Similarly, room temperature superconductors could inexorably revolutionize our way of living for the better. I mean, who knows? Nobody knows! It’s yet to be invented.

Sukbae and Kim claimed that LK-99 displayed superconductivity when the temperature dropped below 127C. They claimed to have observed zero resistance currents.

And that was all it took for social media savvy tech entrepreneurs to embark on a hype train, and spread the word on room temperature superconductors potentially being real at last. Except it’s not technically room temperature – for 127C is way past the boiling point of water. But it’s much easier for laboratories to set up an experiment, investigate and replicate 127C.

The dream fever isn’t abating away, but the proof really is in the pudding.

There’s nothing to say room temperature superconductors can’t exist. In fact, scientists who worked in producing these results have also shared this opinion in their work.

Conventional superconductivity – with extreme cold critical temperatures – was challenged back in 1986, when certain cuprate compounds such as yttirium barium copper oxide (or YBCO) were discovered. They have a higher critical temperature of -183C, which is still very cold, but still warmer compared to helium-4. Such critical temperatures are outside the realm of the standard BCS theory, with the main mechanisms underpinning them being a topic of research.

The race for verification

After their paper was submitted in arXiv, Sukbae and Kim released a video of the levitating LK-99 sample on a magnet – a hallmark signature of the Meissner effect. The Meissner effect is a prediction of the standard BCS theory – when magnetic field lines are ousted from within the material itself.

They provided a detailed description of how LK-99 can be synthesised. This led materials labs from across the world to descend into a frenzy to try and replicate their results. 

Some of the earliest research were done at the National Physics Laboratory (NPL) in New Delhi and Beihang University in Beijing (BU).

A team from the Southeast University in Nanjing, observed a near-zero resistance in LK-99 at -163 C. The team from Nanjing used an X-ray diffraction technique consistent with the work that the Korean scientists had published.

And then the theorists entered the fray. Sinead Griffin from the Lawrence Berkeley National Laboratory, US, performed calculations to suggest there really were telltale signs of room temperature super conductance in LK-99. Specifically, possible mechanisms for forming Cooper pairs were identified.

While these results were tantalising, they did not give conclusive evidence of superconductivity.

The Meissner effect – or what the South Koreans claimed was the Meissner effect- couldn’t be replicated in any other studies.

Griffin attained social media popularity after her tweets with over 14K followers on X.  However, truth be told – Griffith wasn’t explicitly backing anybody – but was merely giving the South Koreans’ work a fair shot.

The last twist in the saga came when she said, “My paper did *not* prove nor give evidence of superconductivity”.

Realization dawns

And suddenly, it wasn’t going in LK-99’s favour at all. It turned out the research team at Southeast University in Nanjing, had made incorrect measurements using faulty instrumentation, meaning they were unreliable.

Whereas, the studies from India’s National Physical Laboratory (NPL) and Beihang University didn’t find report any superconductivity effect. In fact, it just seemed like dull, grey metal.

But the final series of nails in the coffin were the conclusive results by Yuan Li at Peking Institute, and Yi Jiang at the Donostia International Physics Centre, Spain. They proved beyond doubt that LK-99, as synthesised by the South Korean team, was a ferromagnet. Yuan Li also explained the levitating video of LK-99 pellets over a magnet was a result of ferromagnetism. He also showed the absence of superconducting current at low temperatures.

A ferrofluid exhibiting ferromagnetic properties; Source: Etienne Desclides / Unsplash

Science is often rife with controversies and debatable results. Many physicists have published unconfirmed, and published plagiarized work. Some notable examples include the alleged groundbreaking work of Jan Schön, who claimed discovery of organic transistors. Only to be charged with fraud after he made up his results, thus bringing him disrepute that brought an end to his scientific career pretty early on.

Then there was the work by Anshu Pandey and Dev Thapa on similar claims of room temperature superconductors that weren’t replicated.

Although it’s unfortunate that this saga ended so disappointingly with LK-99, I am not, in any manner suggestive of the fact that room-temperature superconductivity cannot exist.

Scientists who worked in producing these results have also shared this opinion in their work. Many scientists have however also shared the need to understand the results and related nitty gritty, before jumping the gun.

However, the collaboration amongst scientists at universities across the world, was focused on uncovering LK-99’s true properties.

It wasn’t just mere claims, backed by data, but also the peer-review process that helped redefine public discourse, and set the facts straight. And that had made all the difference.

Rutvij Gholap is a PhD student at the University of Manchester. He is currently working under the supervision of Dr Saeed Bahramy in condensed matter theory. His current research deals with quantum phenomena in two-dimensional materials. Rutvij also holds a first-class Master’s Degree in Physics from the University of Manchester. Among his other achievements, Rutvij also ranked third in the National Physics Olympiad in the UAE and had the opportunity to represent the UAE in the 2017 International Physics Olympiad (IPHO)

Space & Physics

Study Shows Single Qubit Can Outperform Classical Computers in Real-World Communication Tasks

This new research, however, offers compelling evidence of quantum systems’ power in a real-world scenario

Avatar

Published

on

Image credit: Gerd Altmann /Pixabay

Breakthrough Study Shows Quantum Systems Can Outperform Classical Computers in Real-World Communication Tasks

A new study from the S. N. Bose National Centre for Basic Sciences in West Bengal, India, in collaboration with international teams has revealed that even the simplest quantum system, a single qubit, can surpass its classical counterpart in certain communication tasks. This discovery reshapes our understanding of quantum computing and hints at a future where quantum technologies could solve problems that classical computers, even with ample resources, cannot.

Quantum systems have long been seen as the next frontier in computing, with the potential to revolutionize technology. However, proving their superiority over classical systems has been a challenge, as experiments are complex, and limitations often arise that suggest quantum advantage might not be as accessible as once thought. This new research, however, offers compelling evidence of quantum systems’ power in a real-world scenario.

Professor Manik Banik and his team at the S. N. Bose Centre, alongside researchers from the Henan Key Laboratory of Quantum Information and Cryptography, Laboratoire d’Information Quantique, University libre de Bruxelles, and ICFO—the Barcelona Institute of Science and Technology, have demonstrated that a single qubit can outperform a classical bit in a communication task, even when no extra resources, like shared randomness, are available. The theoretical study, published in Quantum, was accompanied by an experimental demonstration featured as an Editors’ Suggestion in Physical Review Letters.

The team’s innovative approach involved developing a photonic quantum processor and a novel tool called a variational triangular polarimeter

The key to this breakthrough lies in the way quantum and classical systems handle communication. Classical communication often relies on shared resources, such as pre-agreed random numbers, to function efficiently. Without these shared resources, the task becomes more challenging. In contrast, the researchers found that a qubit does not require such help and can still outperform a classical bit under the same conditions.

The team’s innovative approach involved developing a photonic quantum processor and a novel tool called a variational triangular polarimeter. This device enabled them to measure light polarization with high precision using a technique known as Positive Operator-Valued Measurements (POVM). These measurements play a crucial role in understanding the behavior of quantum systems, particularly under realistic conditions that include noise.

Credit: PIB

“This result is particularly exciting because it demonstrates a tangible quantum advantage in a realistic communication scenario,” said Professor Banik. “For a long time, quantum advantage was mostly theoretical. Now, we’ve shown that even a single qubit can outperform classical systems, opening up new possibilities for quantum communication and computing.”

Credit: PIB

This research represents more than just an academic milestone; it brings us a step closer to a future where quantum technologies could drastically alter how we process and communicate information. As quantum systems continue to develop, this breakthrough makes the divide between quantum and classical computing not only more fascinating but also more attainable. The study also signals that quantum systems may eventually be able to solve problems that classical computers struggle with, even when resources are limited.

With this discovery, the potential for quantum communication and computation is moving from theoretical to practical applications, making the future of quantum technologies look even more promising.

Continue Reading

Space & Physics

IIT Kanpur Unveils World’s First BCI-Based Robotic Hand Exoskeleton for Stroke Rehabilitation

The BCI-based robotic hand exoskeleton utilizes a unique closed-loop control system to actively engage the patient’s brain during therapy

Avatar

Published

on

Image credit: By Special arrangement

The Indian Institute of Technology Kanpur (IITK) has unveiled the world’s first Brain-Computer Interface (BCI)-based Robotic Hand Exoskeleton, a groundbreaking innovation set to revolutionize stroke rehabilitation. This technology promises to accelerate recovery and improve patient outcomes by redefining post-stroke therapy. Developed over 15 years of rigorous research led by Prof. Ashish Dutta from IIT Kanpur’s Department of Mechanical Engineering, the project was supported by India’s Department of Science and Technology (DST), UK India Education and Research Initiative (UKIERI), and the Indian Council of Medical Research (ICMR).

The BCI-based robotic hand exoskeleton utilizes a unique closed-loop control system to actively engage the patient’s brain during therapy. It integrates three key components: a Brain-Computer Interface that captures EEG signals from the motor cortex to detect the patient’s intent to move, a robotic hand exoskeleton that assists with therapeutic hand movements, and software that synchronizes brain signals with the exoskeleton for real-time feedback. This coordination helps foster continuous brain engagement, leading to faster and more effective recovery.

“Stroke recovery is a long and often uncertain process. Our device bridges the gap between physical therapy, brain engagement, and visual feedback creating a closed-loop control system that activates brain plasticity, which is the brain’s ability to change its structure and function in response to stimuli,” said Prof. Ashish Dutta. “This is especially significant for patients whose recovery has plateaued, as it offers renewed hope for further improvement and regaining mobility. With promising results in both India and the UK, we are optimistic that this device will make a significant impact in the field of neurorehabilitation.”

Traditional stroke recovery often faces challenges, especially when motor impairments stem from damage to the motor cortex. Conventional physiotherapy methods may fall short due to limited brain involvement. The new device addresses this gap by linking brain activity with physical movement. During therapy, patients are guided on-screen to perform hand movements, such as opening or closing their fist, while EEG signals from the brain and EMG signals from the muscles are used to activate the robotic exoskeleton in an assist-as-required mode. This synchronization ensures the brain, muscles, and visual engagement work together, improving recovery outcomes.

Pilot clinical trials, conducted in collaboration with Regency Hospital in India and the University of Ulster in the UK, have yielded impressive results. Remarkably, eight patients—four in India and four in the UK—who had reached a recovery plateau one or two years post-stroke achieved full recovery through the BCI-based robotic therapy. The device’s active engagement of the brain during therapy has proven to lead to faster and more comprehensive recovery compared to traditional physiotherapy.

While stroke recovery is typically most effective within the first six to twelve months, this innovative device has demonstrated its ability to facilitate recovery even beyond this critical period. With large-scale clinical trials underway at Apollo Hospitals in India, the device is expected to be commercially available within three to five years, offering new hope for stroke patients worldwide.

Continue Reading

Space & Physics

Obituary: R. Chidambaram, Eminent Physicist and Architect of India’s Nuclear Program

Rajagopala Chidambaram (1936–2025), a man whose work shaped the future of modern India, will always be remembered as the chief architect of India’s nuclear journey.

Avatar

Published

on

Rajagopala Chidambaram, a world-class physicist and the chief architect of India’s nuclear program, passed away on January 4, 2025, at the age of 88. Renowned for his unparalleled contributions to India’s nuclear defense and energy security, Chidambaram leaves a profound legacy in both the scientific community and the nation’s strategic defense apparatus.

Born on November 11, 1936, in India, Dr. Chidambaram was an alumnus of Presidency College, Chennai, Tamil Nadu, and the Indian Institute of Science, Bengaluru, Karnataka. His academic background, coupled with his innate curiosity and vision, led him to become one of India’s foremost scientific minds. Throughout his illustrious career, Dr. Chidambaram played an instrumental role in shaping India’s nuclear capabilities, overseeing both the Pokhran-I (1974) and Pokhran-II (1998) nuclear tests, which cemented India’s position as a nuclear power on the world stage.

As a physicist, Dr. Chidambaram’s groundbreaking research in high-pressure physics, crystallography, and materials science greatly advanced the understanding of these fields. His pioneering work laid the foundation for modern materials science research in India, contributing to the nation’s scientific progress in multiple areas. His expertise in these complex disciplines not only bolstered India’s nuclear research but also advanced its technological prowess.

In addition to his work in nuclear weapons development, Dr. Chidambaram made significant strides in nuclear energy, ensuring that India remained at the forefront of scientific and technological advancements. As Director of the Bhabha Atomic Research Centre (BARC) and later as Chairman of the Atomic Energy Commission of India, he was integral to India’s peaceful nuclear energy initiatives. As Principal Scientific Adviser to the Government of India, Dr. Chidambaram guided national policies on defense, energy, and nuclear research, shaping the future of India’s scientific endeavors.

He was a vital member of the team that conducted India’s first nuclear test, Smiling Buddha, at Pokhran in 1974. His leadership during the Pokhran-II tests in 1998, which confirmed India’s nuclear deterrent, was a defining moment in the nation’s history. Chidambaram’s steadfast commitment to India’s defense and scientific advancement earned him respect both at home and abroad.

Rajagopala Chidambaram captured during the session ‘Innovative India’ at the Annual Meeting 2008 of the World Economic Forum in Davos, Switzerland. Copyright by World Economic Forum/Photo by Monika Flueckiger

A visionary leader, Dr. Chidambaram believed in the power of science and technology to drive national development. His efforts were instrumental in championing key initiatives in energy, healthcare, and strategic self-reliance. He steered numerous projects that significantly advanced India’s science and technology landscape. Notably, he played a central role in the indigenous development of supercomputers and was the driving force behind the conceptualization of the National Knowledge Network, which connected research and educational institutions across India.

Dr. Chidambaram was also an ardent advocate for the application of science and technology to improve societal conditions. He established the Rural Technology Action Groups and the Society for Electronic Transactions and Security, among other programs. His emphasis on “Coherent Synergy” in India’s scientific efforts helped foster collaboration across various disciplines, accelerating the country’s scientific growth.

On the global stage, Dr. Chidambaram served as the Chairman of the Board of Governors of the International Atomic Energy Agency (IAEA) in 1994-1995 and contributed to several high-level international nuclear discussions. His expertise was sought worldwide, and in 2008, he was appointed to the Commission of Eminent Persons by the IAEA to assess the agency’s role in nuclear governance.

He was a vital member of the team that conducted India’s first nuclear test, Smiling Buddha, at Pokhran in 1974

In recognition of his exceptional contributions to science and national development, Dr. Chidambaram received several prestigious accolades, including the Padma Shri in 1975 and the Padma Vibhushan in 1999. He was also awarded honorary doctorates from several universities and was a fellow of several eminent Indian and international scientific academies.

Dr. Chidambaram’s passing marks the end of an era for India’s nuclear program and the global scientific community. His legacy as a scientist, visionary leader, and architect of India’s nuclear journey will continue to inspire future generations. His contributions to national security, energy, and technological innovation have left an indelible mark on India’s scientific and strategic landscape.

Rajagopala Chidambaram’s profound impact on India’s nuclear and scientific trajectory will be remembered for generations to come. His work in advancing both national defense and the peaceful use of nuclear energy stands as a testament to his vision of a self-reliant, scientifically empowered India.

“Deeply saddened by the demise of Dr Rajagopala Chidambaram. He was one of the key architects of India’s nuclear programme and made ground-breaking contributions in strengthening India’s scientific and strategic capabilities. He will be remembered with gratitude by the whole nation and his efforts will inspire generations to come,” Prime Minister Narendra Modi wrote on X.

Dr. Ajit Kumar Mohanty, Secretary, Department of Atomic Energy, in a statement issued, said,  “Dr. Chidambaram was a doyen of science and technology whose contributions furthered India’s nuclear prowess and strategic self-reliance. His loss is an irreparable one for the scientific community and the nation.”

Continue Reading

Trending