Qubits on the Bloch
World Expo 2025 Swiss Pavilion
Osaka, Japan
Qubits are the fundamental units of quantum computers. In Qubits on the Bloch, test chips are mounted on conceptual Bloch spheres and contain real semiconductor qubits. The installation reveals the intricate dialogue between theory and experiments and the interplay between art and science. In the quantum journey, each step, from testing to setbacks, contributes to the evolving frontier of innovation.
Installation components
- the spheres
The spheres represents the Bloch spheres and are covered with real chips with qubits used in our laboratories. The Bloch sphere is an abstract representation that physicists use to describe all possible states a qubit can occupy. The golden pads on the chips serve as electrical contacts, allowing us to connect the qubits to precision instruments for control and measurement.
The installation components
- the video
The video offers an artistic journey into the quantum world, visualizing fundamental quantum principles, listed below.
Wave-particle duality is a fundamental concept in quantum mechanics that states that every particle or quantum entity (like electrons and photons) exhibits both wave-like and particle-like properties.
In this first representation of a particle (the video frame below), it is represented as a moving and changing entity to embody the wave-like nature of the particle. Yet, they are still distinguishable as individual entities, to embody the fact that they can also act as particles.
Entanglement is a quantum phenomenon by which two particles are linked by a relationship. By measuring one of them, we immediately learn something about the other one, no matter how far apart they are.
In the video, this phenomenon is represented by the light ray linking the two entities.
Quantum superposition is a fundamental principle of quantum mechanics that states a quantum system can exist in multiple states at once—until it is measured.
In the video, it is represented as two entities superimposing.
The Bloch sphere is a powerful visual representation of the state of a single qubit—the basic unit of quantum information. It shows how a qubit’s state can be a superposition of the classical states ∣0⟩ and ∣1⟩ in a 3D space.
Basics of the Bloch Sphere:
It's a unit sphere, where any point on the surface represents a pure state of a qubit.
The north pole is the state ∣0⟩∣0⟩,
The south pole is the state ∣1⟩∣1⟩,
Any other point represents a superposition
In the video, the Boch sphere is represented as a sphere with a rotation arrow inside. The arrow can be viewed as pointing at different superposition states that the qubit can take.
The arrow inside the circle can also be interpreted as a representation of the spin of an electron or hole acting as a spin qubit, the type of qubit that NCCR SPIN is working on.
Want to learn more? Here are some fundamentals about quantum computers and what NCCR SPIN is working on
Credits
The project was directed by Maria Longobardi.
The artwork was conceptualised and developed by Maria Longobardi and Marie Le Dantec.
The spheres were constructed by M. Carballido, P. Chevalier Kwon, and M. Le Dantec.
The video was created by visual artist Luca Scarzella.
Quantum Computing Unplugged was developed, written and illustrated by Pierre Chevalier-Kwon, Pierre Fromholz, Miguel Carballido and Marie Le Dantec.