Technology-Watching: Quantum Microchips Connected in Record-Breaking World First

[from UK Research and Innovation]

Researchers in the UK have successfully transferred data between quantum microchips for the first time.

This helps overcome a key obstacle to building a commercial quantum computer.

The milestone achieved by a team from the University of Sussex and Brighton-based quantum computer developer Universal Quantum, allows chips to be linked like a jigsaw.

On track to useful quantum computers

It means that many more qubits, the basic calculating unit, can be joined together than is possible on a single microchip. This will make a more powerful quantum computer possible.

The project, which has been backed by the Engineering and Physical Sciences Research Council (EPSRC), has also broken the world record for quantum connection speed and accuracy.

The scaling of qubit numbers from the current level of around 100 qubits to nearer 1 million is central to creating a quantum processor that can make useful calculations.

The significant achievement is based on a technical blueprint for creating a large-scale quantum computer, which was first published in 2017 with funding from EPSRC.

Within the blueprint was the ground-breaking concept successfully demonstrated with this research of linking quantum computing modules with electrical fields.

Unlocking UK potential

The UK is a leader in the global race to develop useful quantum computers, which represent a step-change in computing power.

Their development may help solve pressing challenges from drug discovery to energy-efficient fertilizer production. But their impact is expected to sweep across the economy, transforming most sectors and all our lives.

Potential to scale up

Winfried Hensinger, Professor of Quantum Technologies at the University of Sussex and Chief Scientist and co-founder at Universal Quantum said:

As quantum computers grow, we will eventually be constrained by the size of the microchip, which limits the number of quantum bits such a chip can accommodate.

In demonstrating that we can connect 2 quantum computing chips, a bit like a jigsaw puzzle, and, crucially, that it works so well, we unlock the potential to scale up by connecting hundreds or even thousands of quantum computing microchips.

Speed and precision

The researchers were successful in transporting the qubits using electrical fields with a 99.999993% success rate and a connection rate of 2424 transfers per second. Both numbers are world records.

Dr. Kedar Pandya, Director of Cross-Council Programmes at EPSRC, said:

This significant milestone is evidence of how EPSRC funded science is seeding the commercial future for quantum computing in the UK.

The potential for complex technologies, like quantum, to transform our lives and create economic value widely relies on visionary early-stage investment in academic research.

We deliver that crucial building block and are delighted that the University of Sussex and its spin-out company, Universal Quantum, are demonstrating the strength it supports.

Institute of Physics award winner

Universal Quantum has been awarded €67 million from the German Aerospace Center to build 2 quantum computers.

The University of Sussex spin-out was also recently named as one of the 2022 Institute of Physics award winners in the business start-up category.

India and the Russia-Ukraine War: The Paradox of Military Dependence, Traditional Loyalty and Strategic Autonomy

[from India in Transition, published by the Center for the Advanced Study of India (CASI) of the University of Pennsylvania, by Arndt Michael]

India, long-established as the world’s most populous democracy, has been quite instrumental over the years in assisting various countries dealing with democratic struggles. This support has included a blend of bilateral and multilateral initiatives, and especially economic development projects. Yet, India’s recent attitude toward the Russian attack on Ukraine and its concomitant behavior in the United Nations Security Council (as a non-permanent member) seems to contradict its support of democracy. By abstaining, rather than explicitly voting in favor of UN resolutions condemning Russian aggression at the beginning of the war, India angered several UN member-countries.

In order to substantiate its abstention from voting, India felt compelled to issue a so-called “Explanation of Vote” (EoV). In it, India asked for a “return to the path of diplomacy” and an immediate cessation of “violence and hostilities.” Crucially, India stated in the EoV that “the contemporary global order has been built on the UN Charter, international law, and respect for the sovereignty and territorial integrity of states…all member states need to honor these principles in finding a constructive way forward. Dialogue is the only answer to settling differences and disputes, however daunting that may appear at this moment.” 

While these statements and the call for dialogue are in accordance with India’s professed stance toward the relevance and objectives enshrined in the UN Charter, the discrepancy between rhetoric and practice is still conspicuous. At first glance, a “good” relationship with Russia seems to be more significant than the expectations of the world-community as represented in the United Nations. And, more importantly, by abstaining, India seemingly violated one of its central foreign and strategic policies: to always strive for strategic autonomy.

However, from a strategic perspective, India is precisely replicating what it did when the Soviet Union invaded Afghanistan. For India, its own national security is at stake, as well as its current and future geostrategic influence in Asia and the world. The military dependence that currently exists between India and Russia is nothing short of gigantic and has created a dangerous conundrum. Since the “Indo–Soviet Treaty of Peace, Friendship and Cooperation” was signed in 1971, defense agreements and long-term supply contracts have been in place. And while India and Russia have shared a strategic relationship since October 2000, this was upgraded in December 2020 to a “Special and Privileged Strategic Partnership.” 

Although there was a marked reduction of Russian imports in past years, official data from the Stockholm International Peace Research Institute (SIPRI) reveal that between 1996-2015, the Russian proportion of Indian military imports was almost 70 percent, and between 2016-20 it still hovered around 49 percent. In fact, 70 percent of all Indian military equipment currently in use has been directly produced in Russia, was manufactured with the majority of parts coming from Russia, or licensed by Russia. In 2020, this included the majority of Indian tanks, the only aircraft carrier (the INS Vikramaditya, a heavily modified Kiev-class aircraft carrier) with all of its combat aircraft MiG-29s, six frigates, four destroyers and the only nuclear-powered submarine. Additionally, eight out of fourteen Indian Navy submarines belong to the Russian Kilo-class. The Indian Air Force flies Sukhoi Su-30MKIs and Mil Mi-17s, which, respectively, constitute the largest share of the combat aircraft and utility helicopters, in addition to Russian tanker planes. India also just recently purchased the S-400 missile system.

Even though India has begun to reorient itself militarily toward other countries—the U.S., Israel, France and Italy—and has substituted foreign imports by slowly developing its own capabilities, a large number of new Indo-Russian projects are in the conceptual or implementation stages. In December 2021, in the frame of the so-called “2+2 Dialogue” (foreign and defense ministers), India and Russia began a new phase in their militarytechnological cooperation. Incidentally, India has used this very format for furthering cooperation in strategic, security and intelligence issues with four of its key strategic partners: Australia, the U.S., Japan and the newly added Russia. Russia and India agreed upon a further deepening of mutual military relations for ten years (until 2031). What is new is that next to the traditional purchase of Russian weapons systems, many common research projects and the development of new weapons systems—with their production taking place equally in both countries—have been agreed upon. This production includes new frigates, helicopters, submarines, cruise missiles and even Kalashnikovs

The depth of this mutual engagement, and especially India’s dependence, highlights a huge dilemma that might not only have drastic strategic consequences, but also long-lasting regional repercussions. The worldwide sanctions issued against Russia aim at the Russian economy and military. When it comes to the procurement of such crucial components as microchips or airline parts, Russia is soon expected to face shortages, essentially crippling its capacity to repair, construct, or have spare parts available (let alone construct new equipment). Unless other countries, such as China, circumvent international sanctions and step-in, the expected Russian inability to take care of its own military will have a spill-over effect. Russia is unlikely to be able to fulfill its contractual obligations toward India, and the lack of spare parts also has the potential to cripple India’s own military with regards to the Russian weapons equipment. The procurement agreements and common projects are, hence, all in jeopardy and India, now more than ever, depends on Russian goodwill. 

Next to military dependence, there are other concomitant effects in the economic and political sphere that influence Indian voting behavior. The worldwide sanctions have already led to dramatic increases in oil and gas prices, with India relying on imports of up to 80 percent. India will, therefore, have to pay much more for such crucial imports. Military imports from other countries aimed at substituting Russian equipment will also be much more expensive. All of this deals the Indian economy another blow—an economy that has been especially hit hard by the COVID-19 pandemic. And politically, Indian hegemony in South Asia has been markedly under pressure, in no small part because of the ChinaPakistan axis. In the eyes of India, this axis poses a serious threat to an already highly volatile IndoPakistan relationship. In addition, the IndoChina relationship reached a new low in May 2020 when Chinese infrastructure projects along the Himalayan borderlands led to fighting and the killing of soldiers. In addition, the Chinese claims to the South China Sea are categorically disputed by India. Chinese overtures toward Sri Lanka, the Maldives, and especially Pakistan in the frame of the Road Initiative are also regarded with growing discontent, as India claims that China is following a policy of encircling India.

In its 75th year of independence, India is following a classic realpolitik in trying not to alienate Russia while pledging rhetorical support for Ukraine. The contradictory consequence is that Russia has now offered more discounted oil, gas, and investments, while at the same time, the UK has suggested its military relationship with India could be upgraded—and has offered weapons made in the UK. For the Indian political establishment, India cannot forgo Russian support, militarily or as a producer of cheap oil and gas. Going forward, India’s military will need to protect its national security and project Indian influence and power well beyond its borders.

Arndt Michael is a Lecturer in the Department of Political Science, University of Freiburg (Germany), author of the multi-award-winning book India’s Foreign Policy and Regional Multilateralism (Palgrave Macmillan, 2013), and co-editor of Indien Verstehen (Understanding India, Springer, 2016). His articles have been published in Asian Security, Cambridge Review of International Affairs, Harvard Asia Quarterly, India Quarterly and India Review.

New Ultrathin Capacitor Could Enable Energy-Efficient Microchips

Scientists turn century-old material into a thin film for next-gen memory and logic devices

[from Berkeley Lab, by Rachel Berkowitz]

Electron microscope images show the precise atom-by-atom structure of a barium titanate (BaTiO3) thin film sandwiched between layers of strontium ruthenate (SrRuO3) metal to make a tiny capacitor. (Credit: Lane Martin/Berkeley Lab)

The silicon-based computer chips that power our modern devices require vast amounts of energy to operate. Despite ever-improving computing efficiency, information technology is projected to consume around 25% of all primary energy produced by 2030. Researchers in the microelectronics and materials sciences communities are seeking ways to sustainably manage the global need for computing power.

The holy grail for reducing this digital demand is to develop microelectronics that operate at much lower voltages, which would require less energy and is a primary goal of efforts to move beyond today’s state-of-the-art CMOS (complementary metaloxide semiconductor) devices.

Non-silicon materials with enticing properties for memory and logic devices exist; but their common bulk form still requires large voltages to manipulate, making them incompatible with modern electronics. Designing thin-film alternatives that not only perform well at low operating voltages but can also be packed into microelectronic devices remains a challenge.

Now, a team of researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have identified one energy-efficient route—by synthesizing a thin-layer version of a well-known material whose properties are exactly what’s needed for next-generation devices.

First discovered more than 80 years ago, barium titanate (BaTiO3) found use in various capacitors for electronic circuits, ultrasonic generators, transducers, and even sonar.

Crystals of the material respond quickly to a small electric field, flip-flopping the orientation of the charged atoms that make up the material in a reversible but permanent manner even if the applied field is removed. This provides a way to switch between the proverbial “0” and “1” states in logic and memory storage devices—but still requires voltages larger than 1,000 millivolts (mV) for doing so.

Seeking to harness these properties for use in microchips, the Berkeley Lab-led team developed a pathway for creating films of BaTiO3 just 25 nanometers thin—less than a thousandth of a human hair’s width—whose orientation of charged atoms, or polarization, switches as quickly and efficiently as in the bulk version.

“We’ve known about BaTiO3 for the better part of a century and we’ve known how to make thin films of this material for over 40 years. But until now, nobody could make a film that could get close to the structure or performance that could be achieved in bulk,” said Lane Martin, a faculty scientist in the Materials Sciences Division (MSD) at Berkeley Lab and professor of materials science and engineering at UC Berkeley who led the work.

Historically, synthesis attempts have resulted in films that contain higher concentrations of “defects”—points where the structure differs from an idealized version of the material—as compared to bulk versions. Such a high concentration of defects negatively impacts the performance of thin films. Martin and colleagues developed an approach to growing the films that limits those defects. The findings were published in the journal Nature Materials.

To understand what it takes to produce the best, low-defect BaTiO3 thin films, the researchers turned to a process called pulsed-laser deposition. Firing a powerful beam of an ultraviolet laser light onto a ceramic target of BaTiO3 causes the material to transform into a plasma, which then transmits atoms from the target onto a surface to grow the film. “It’s a versatile tool where we can tweak a lot of knobs in the film’s growth and see which are most important for controlling the properties,” said Martin.

Martin and his colleagues showed that their method could achieve precise control over the deposited film’s structure, chemistry, thickness, and interfaces with metal electrodes. By chopping each deposited sample in half and looking at its structure atom by atom using tools at the National Center for Electron Microscopy at Berkeley Lab’s Molecular Foundry, the researchers revealed a version that precisely mimicked an extremely thin slice of the bulk.

“It’s fun to think that we can take these classic materials that we thought we knew everything about, and flip them on their head with new approaches to making and characterizing them,” said Martin.

Finally, by placing a film of BaTiO3 in between two metal layers, Martin and his team created tiny capacitors—the electronic components that rapidly store and release energy in a circuit. Applying voltages of 100 mV or less and measuring the current that emerges showed that the film’s polarization switched within two billionths of a second and could potentially be faster—competitive with what it takes for today’s computers to access memory or perform calculations.

The work follows the bigger goal of creating materials with small switching voltages, and examining how interfaces with the metal components necessary for devices impact such materials. “This is a good early victory in our pursuit of low-power electronics that go beyond what is possible with silicon-based electronics today,” said Martin.

“Unlike our new devices, the capacitors used in chips today don’t hold their data unless you keep applying a voltage,” said Martin. And current technologies generally work at 500 to 600 mV, while a thin film version could work at 50 to 100 mV or less. Together, these measurements demonstrate a successful optimization of voltage and polarization robustness—which tend to be a trade-off, especially in thin materials.

Next, the team plans to shrink the material down even thinner to make it compatible with real devices in computers and study how it behaves at those tiny dimensions. At the same time, they will work with collaborators at companies such as Intel Corp. to test the feasibility in first-generation electronic devices. “If you could make each logic operation in a computer a million times more efficient, think how much energy you save. That’s why we’re doing this,” said Martin.

This research was supported by the U.S. Department of Energy (DOE) Office of Science. The Molecular Foundry is a DOE Office of Science user facility at Berkeley Lab.