Stewart Smith

Stewart Smith is a digital artist and virtual reality technologist.

Stewart has a long history of operating at the intersection of art and science, from creating digital artworks in collaboration with the Center for Art and Media (ZKM) in Germany, to working within Google’s Creative Lab and Data Arts Team, to his current role as Head of Consumer Augmented Reality at Unity Technologies where he’s helping to craft the future of augmented and virtual reality creation. Although Stewart taught himself to program computers at a young age, he pursued an academic interest in art rather than computer science, receiving his MFA in graphic design from Yale University. Stewart’s artworks have been exhibited at the Museum of Modern Art in New York, ZKM in Germany, the SFMOMA in San Francisco, and is in the permanent collection of the Fondation Cartier in Paris. Over the past few years, he’s taken a deep interest in quantum computing—teaching himself the logic of quantum circuits by building Q.js, an open-source, browser-based quantum circuit composer and circuit simulator.

Beneath The Green, The Quantum

The installation

"Beneath The Green, The Quantum" premiered on June 23, 2023 at the International Festival of Arts and Ideas.

Artist Stewart Smith has designed a human-scaled light installation, in collaboration with Yale Quantum Institute researchers and students, that investigates the latest in quantum error correction research—an essential tool in the pursuit of fault-tolerant quantum computing. Visitors are invited to circulate through this interactive forest of vertical illuminated beacons; their bodies acting as proxies for the destructive quantum noise and decoherence that arises within a quantum device as it operates. In response, the illuminated beacons recognize these “quantum errors” and attempt to mitigate them in real-time, illustrated through patterns of light that ripple across the collective. This attempt to resolve observer-induced “error” is driven by actual quantum error correcting algorithms researched and developed at Yale University.

The standing light beacons gently allude to the New Haven Green’s spooky history as a temporary respite for souls en route to a rapturous beyond; metaphorically drawing energy from beneath the grassy surface and transmitting it heavenward—like a photon traversing an impossible barrier in the cold, dark, and isolated environment of a quantum device’s dilution refrigeration tank. And just as the beach hides beneath the paving stones, perhaps a united future of students and workers can grow from this soil of uncertainty, seeded by the momentum of generative artificial intelligence and new forms of computation that promise to redefine what it is to labor, produce, and consume.

We invite you to traverse our small forest of light, weaving your own path of human error—as we all do—through the spaces between. And don’t fret. Our algorithms can tidy up.

Time-lapse of the installation: notice at the end how the light beacons return to blue once the public does not trigger the motion sensors creating errors in the system.

The Science: Quantum Error Correction

A qubit (quantum-bit) is the basic unit of information in quantum computing and counterpart to the bit (binary digit) in classical computing. Qubits are very sensitive to quantum noise or decoherence, and their lifetime is measured in microseconds. You will have less than this time to encode your data and perform a calculation before you lose your information to randomness.
Quantum Error Correction (QEC) algorithms allow you to find the errors as they occur and correct them to expand the life of your qubit. If you go fast enough, you can perform Real Time QED. Using this technique, researchers at YQI have, for the first time in March 2023, more than doubled the lifetime of a qubit, up to 180 microseconds! (learn more about this here)

This interactive light installation represents a virtual array of 25 data qubits (black square) like they could be used in a quantum computer. Each virtual qubit is surrounded by four stabilizers (orange circles on diagram, light beacons with motion sensors in the installation) that monitor for errors.
If an error is detected, randomly, a diagonal lights up (top left or top right, but always in pair). When visitors enter the installation and stand in between the light beacons, they trigger motion sensors which causes an error to the qubit.
The light beacons will detect the error and light up, alerting the system to perform our Quantum Error Correction algorithm to tidy up and reset the qubit to the correct state.

Steps taken by the Quantum Error Correction Algorithm
Developed by Yue Wu, Computer Science Ph.D. Student at Yale

  • Step 1: Measure all the stabilizers and look for errors
  • Step 2: From the errors, look for the stabilizers around
  • Step 3: Expand the search until you can connect all the errors together or to the edge
  • Step 4: Find the shortest path between errors and send the correction to these qubits

For more information and to play with this interface, visit Yue's Fusion Blossom here.

The Hardware & Code

Inspired by Badger, the now decommissioned dilution refrigerator which ran the world’s first demonstration of two-qubit algorithms with a superconducting quantum processor in 2009 (Visit the exhibition "The Quantum Revolution: Handcrafted in New Haven" the learn more about Badger and quantum hardware here), Stewart Smith designed a light beacon with similar proportions.

Prototyped and built by Alpay Kasal and his team at Bignoodle, each light beacon features 75 individually addressable LEDs, a proximity sensor, a WIFI-enable microcontroller and a battery pack. When turned on, the beacon connects to the local wifi and execute the light pattern streamed from Yue Wu and Stewart Smith's code (available on GitHub here) and send proximity data to indicate whether it detects a visitor (and therefore has an error).

The creative team of Beneath The Green, The Quantum

Artist: Stewart Smith
Scientist: Yue Wu
Hardware: Alpay Kasal and his team at Bignoodle
Producer: Florian Carle

Residency Pictures