The Quantum Revolution: Handcrafted in New Haven
A science and art exhibition on quantum devices
This is a tale of New Haven, one that fits into the astonishing array of makers, thinkers, inventors, and workers who have come before in the Elm City.
In the late 1990s, in the laboratories of the Becton Center at Yale University, overlooking the Grove Street Cemetery, a small revolution started! Experimentalists and theorists began to focus their attention on quantum mechanics (a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles), leveraging its properties to build a new type of computer that could, in theory, outperform any of our current modern computers.
After a decade of hard work and several technological breakthroughs, Yale researchers developed an entire new field of research (circuit quantum electrodynamics or cQED), invented a new type of circuits that behave like atoms, called superconducting qubits (quantum bits), and in 2009, ran the world’s first demonstration of two-qubit algorithms with a superconducting quantum processor inside a dilution refrigerator called Badger.
We hope to show you what an incredible set of achievements this is. Scattered around the room are cavities, qubits, and substrates (the nuts and bolts of quantum architecture), all invented and handcrafted in New Haven by a generation of researchers. The handcrafted nature of each device gives individual fridges a unique look, function, and characteristics, which prompted Yale Quantum Institute Artist-in-Residence Martha Willette Lewis to create “fridge” portraits of these chilly mechanisms. For over 20 years, researchers in New Haven have built strong, meaningful relationships with their machines. Each fridge has a unique look, name, function, and story that we invite you to discover here.
We are today at the very early stages of quantum computing, at the juncture when a superconducting quantum device (the early prototypes of quantum computers) takes up a whole room, and yet is barely capable of an infinitesimal fraction of the computational power of your smartphone. Globally, scientists are building unique machines in their laboratories to try to make sense of a complex and intriguing paradigm of the quantum regime. All of the devices you see here were invented in New Haven and have been widely adopted globally by academic groups and tech giants like Google, IBM, and Intel, who are racing to commercialize the first functioning quantum computer capable of outperforming a classical computer.
Since history is written by the winners, we want to capture this moment in time, when quantum computer prototypes were handcrafted in New Haven, before the commercialization of quantum computers rewrites this history.
What Is a Quantum Computer?
A Quantum computer is a radically new type of computer that harnesses the extraordinary and newly discovered power of quantum systems to store, process and communicate information.
Classical computing stores information in bits represented by a discrete number of possible states (0 or 1). In a quantum computer, the information is stored in quantum bits or qubits that can be in an infinite number of possible states.
Very complex problems, almost impossible to solve with ordinary computers, could be solved exponentially faster by harvesting the full computational power of quantum computers. Possible applications could improve cybersecurity, develop better drugs, optimize complex systems like airline scheduling or improve modeling for weather forecasting.
Artists at YQI
In 2017, Florian Carle, Manager of the Yale Quantum Institute, created an Artist-in-Residence program. This innovative project brings talented artists into the research laboratories to produce artworks in collaboration with quantum physicists. By exploring art as a medium and leveraging the intersectionality of science and the humanities, the program seeks to increase public understanding and discourse about quantum physics through the perspectives of the collaborative artists. In building this program, the emphasis was placed on connecting specialists from disparate fields for conversation, ideas and expertise. Our aim is to create something truly unique and inspiring for the next generation, and to push the boundaries of our collective knowledge through these interactions.
Martha Willette Lewis, a New Haven-based visual artist, was the inaugural artist to join the Institute. The notebooks and drawings on view in the exhibition document her time in the laboratories and her close collaboration with researchers at the Yale Quantum Institute since she began in 2017.
Thrilling. I get giddy when I think about going into the lab to visit the devices. The mysterious, cantankerous, beautiful fridges. Labors of love and sweat. It’s an exotic situation for me to be in- rooms full of shiny instruments, working away, packed with tiny experiment boxes nestled into their complex bellies, each one with its own preferences, quirks, history, and narrative. This is going away. At least in its current iteration. What I am attracted to here, now, is on the way out, fast. Blink. Gone.
Quantum Research in New Haven
Yale's exploration of quantum computing is first and foremost about basic science, about just exploring the mysteries of the universe.
There's been a second quantum revolution over the last 20 years in which we've not changed the theory, but come to understand its bizarre implications, and in particular its implications for processing information in a completely new way that we had not appreciated before.
Since 1998, Yale has assembled a great team of theoreticians and experimentalists (now one of the largest academic quantum computing groups in the world), bringing together different areas of physics, chemistry, engineering, and materials science to explore how Mother Nature works.
It may well be possible to build large scale quantum computers in the future. This exhibition invites you to discover the steps taken in New Haven in the last 20 years to make this happen.
Grown in the laboratories
“Don’t step here, there’s broken glass everywhere!” cried Rob Schoelkopf. Broom in hand, he tried to sweep the shards off the floor. He worked fast, worried someone might get hurt. On the fourth floor of a Brutalist building overlooking the Grove Street Cemetery on Prospect Street, this glass-strewn space was about to be the stage of a technological breakthrough. However, in 1998, it was still unknown how successful this endeavor would be, and accidents were happening. It was an unpredictable, volatile moment in the lab.
At the time, Rob was at the beginning of his career. Having worked briefly as a Cryogenic Engineer at NASA Goddard Space Flight Center after earning a PhD from Caltech, he was appointed first as a Postdoctoral Associate in Dan Prober's group and then as an Assistant Professor in the Yale Department of Applied Physics and was sharing the laboratory space with the low-temperature physics laboratories. The shattered glass was the result of an explosion by Stanley Mroczkowski’s homemade high-pressure chamber, used to grow sapphire crystals such as the pink one on display in this exhibition.
Stanley was a Polish chemist who met Professor Werner Wolf in England in the 1950s. After working together in the UK, they both moved to Yale in the 1960s and continued their collaboration for more than 50 years, trying to discover the secrets of rare earth compounds whose interesting properties are observable only at very low temperatures. Stanley was a master at growing perfectly pure, thinly-cut crystals that were used as substrates.
“I ran a more-or-less self-contained research operation in our little cinderblock house at the back of Hammond Lab,” wrote Werner Wolf in his book The Education of a Physicist. Rob later recalled the self-contained operation in Room 420 led to the creation of a blast-proof laboratory with cinderblocks and blast mats on the sixth floor of Becton (now hosting graduate students’ offices) for Stanley to safely grow crystals in a high-pressure chamber and confine eventual – and inevitable – explosions.
In 2001, a lifetime of work reached its end when Werner and Stanley retired. Substrates became commercially available, and researchers no longer need to grow crystals in the lab. The dismantling of this lab opened more space on the fourth floor of Becton Center for Rob and a newly appointed professor, Michel Devoret, to expand their operation, each eventually acquiring their first dilution refrigerators.
Here, in the next two decades, Yale researchers in New Haven went on to invent two major types of superconducting qubits (transmon and fluxonium) and founded the field of circuit quantum electrodynamics (cQED).
BADGER
This is Badger, the dilution refrigerator which hosted a series of quantum superconducting qubits experiments. Built in 2002 in the Becton laboratories on Prospect Street, this decommissioned dilution "fridge" famously ran the world’s first two-qubit algorithms with a superconducting quantum processor in 2009.
This was an important technological breakthrough. Experiments hosted inside Badger were the prototypes upon which all the current superconducting devices in Becton are built. Other laboratories and industry leaders (e.g. Google, IBM, Intel) across the world have since widely adopted this technology and incorporated it in their commercial quantum devices.
Badger is one of the 17 dilution refrigerators which run quantum experiments in Becton. Each fridge has a unique name, and story that we invite you to discover in the exhibition catalog, with additional drawings and photos.
THE COLDEST PLACE IN THE UNIVERSE
To observe the effects of quantum mechanics, you need to be at the incredibly small scale of an atom. While some researchers are trapping actual atoms with lasers to do their measurements, Yale researchers figured out they can create special circuits, called superconducting qubits, that would behave like atoms. However, for these to exhibit the same behavior, they need to cool them down to nearly absolute zero (~10 millikelvins or ~ -459 degrees Fahrenheit), colder than outer space! This is most commonly facilitated by using cryogenic systems called dilution refrigerators (“fridges”). These systems employ combinations of helium isotopes to reach these unbelievably cold temperatures.
Badger was known as a “wet” fridge because it uses baths of liquid nitrogen (Na) and helium-4 (4He) to precool the dilution unit (the part capable of cooling down the qubits to close to absolute zero). To accommodate this, researchers had to drill a hole in the floor of the laboratory to fit the Dewar canister (picture a cooler for extremely cold liquids) containing the nitrogen and pulley it up through the floor to cool Badger down.
Newer dilution fridges no longer require the baths to cool down. These are called dry fridges and have a more compact design not requiring a trap door to function.
Qubits & Cavities
The objects in the cases are prototypes of superconducting qubits (qubits are quantum bits, the quantum equivalent of the transistors for classical computers). These have been invented, designed, and built by Yale researchers since 1998. These physical objects behave like artificial atoms and allow the researchers to harvest the properties of quantum mechanics. However, to observe a quantum regime, they need to be placed into cryogenic systems called dilution refrigerators that can reach almost absolute zero (~10 millikelvins or ~ -459 degrees Fahrenheit).
All this experimental work has been done in close collaboration with theoreticians who laid the groundwork of quantum science with a very coherent theory allowing the use and control of the new quantum devices. It is a daily occurrence at YQI to see experimentalists and theoreticians working together to bring new cavities and qubit designs to life.
Like the fridges, these qubits and cavities have been named by the researchers that made them. Continuing the animal theme started with Schrödinger’s cat, you will find in the lab jellyfishes, tapeworms, hedgehogs, hippopotamuses, octopuses, snails and even some imaginary creatures, such as the “jelly hog”.
During the field's early days, a great deal of tinkering and creativity was required from the researchers to wire the equipment to control and measure the superconducting qubits inside the fridges, giving them each a unique look (see Martha’s drawings on the walls and in the notebooks). As the number of laboratories and industries using them has increased, suppliers now offer standardized machines with some of the wiring preinstalled, leaving researchers more time to focus on their experiments.
Acknowledgements
Florian and Martha would like to thank the Yale Quantum Institute for the financial support of this exhibition. The incredible freedom given to Florian allows him to establish ambitious programs like the Artist-in-Residence, culminating in projects like this one reaching far beyond the laboratories of Yale.
We would like to warmly thank Robert Schoelkopf and Michel Devoret for their constant support and trust, and for graciously allowing us to use freely their laboratories for outreach programs.
Thank you to all the Yale researchers, present and past, who took the time to share their experience and knowledge of the lab with us.
Thank you to the New Haven Museum for hosting this exhibition. Special thanks to Jason Bischoff-Wurstle and Katie Piascyk for their invaluable help on this project.
Credits
Curator: Florian Carle
Artist: Martha Willette Lewis
Photography: Florian Carle & Jessica Smolinski
Scientific Consultant: Zhixin Wang