Qubits, Qutrits, Qudits, .. Why stop at two?
Major
Computer Science
Second Major
Physics
Submission Type
Poster
Area of Study or Work
Physics
Faculty Advisor
Narendra Jaggi
Location
CNS Atrium
Start Date
4-11-2026 11:15 AM
End Date
4-11-2026 12:30 PM
Abstract
The central question that this project tries to address is the following: Dominance of binary logic in classical computing emerged from deep physical and engineering constraints. I ask if similar constraints force quantum computing toward qubits, or whether today's qubit dominance is merely historical and a temporary technological contingency? Quantum computing today appears to be converging on an architectural choice that reminds us of the trajectory of classical computing: the qubit. Nearly all commercial quantum computing platforms — including those developed by IBM, Google, and Amazon — are built around controllable two-level quantum systems. Superconducting circuits, trapped ions, and photonic encodings are engineered so that a two-dimensional Hilbert space functions as the computational unit. Yet quantum theory does not privilege two-level systems. This contrast between what current devices use and what the theory allows motivates a closer look at the higher-dimensional structures already present in quantum mechanics. The mathematical structure of quantum mechanics naturally accommodates arbitrary-dimensional Hilbert spaces. Atoms possess multiple accessible energy levels. Photons carry orbital angular momentum in high-dimensional spaces. Ions and superconducting circuits inherently support more than two levels. In laboratory settings, three-level systems (qutrits) and higher-dimensional qudits have already been implemented and studied with notable success, and I take these results as evidence that the restriction to qubits is a contingent design preference rather than a theoretical necessity. The working hypothesis guiding this project has been that very little appears to transfer from the classical case. Quantum information theory, noise mechanisms, and error correction principles differ fundamentally from their classical counterparts, I focus on how qudits exploit these differences.Therefore, it's possible that dominance of qubits today may reflect temporary engineering convenience and early platform momentum rather than theoretical inevitability.
Qubits, Qutrits, Qudits, .. Why stop at two?
CNS Atrium
The central question that this project tries to address is the following: Dominance of binary logic in classical computing emerged from deep physical and engineering constraints. I ask if similar constraints force quantum computing toward qubits, or whether today's qubit dominance is merely historical and a temporary technological contingency? Quantum computing today appears to be converging on an architectural choice that reminds us of the trajectory of classical computing: the qubit. Nearly all commercial quantum computing platforms — including those developed by IBM, Google, and Amazon — are built around controllable two-level quantum systems. Superconducting circuits, trapped ions, and photonic encodings are engineered so that a two-dimensional Hilbert space functions as the computational unit. Yet quantum theory does not privilege two-level systems. This contrast between what current devices use and what the theory allows motivates a closer look at the higher-dimensional structures already present in quantum mechanics. The mathematical structure of quantum mechanics naturally accommodates arbitrary-dimensional Hilbert spaces. Atoms possess multiple accessible energy levels. Photons carry orbital angular momentum in high-dimensional spaces. Ions and superconducting circuits inherently support more than two levels. In laboratory settings, three-level systems (qutrits) and higher-dimensional qudits have already been implemented and studied with notable success, and I take these results as evidence that the restriction to qubits is a contingent design preference rather than a theoretical necessity. The working hypothesis guiding this project has been that very little appears to transfer from the classical case. Quantum information theory, noise mechanisms, and error correction principles differ fundamentally from their classical counterparts, I focus on how qudits exploit these differences.Therefore, it's possible that dominance of qubits today may reflect temporary engineering convenience and early platform momentum rather than theoretical inevitability.