Researchers create a molecule that works as a qubit, can be read individually with laser light, and may be placed on photonic chips
Researchers at NVision Quantum Technologies and Ulm University have created a molecule that can function as a quantum bit, or qubit, and be read out one molecule at a time using light.
Reported in the journal Nature on 28 October 2026, the work marks an important advance for molecular qubits, which have lagged behind other quantum-computing platforms such as trapped ions, superconducting circuits, and neutral atoms. NVision now aims to place these molecules onto photonic chips.
The molecule, di([1,1′-biphenyl]-4-yl)carbene, meets four key requirements for an individually addressable qubit.
- When excited by a laser, it fluoresces in only one of its three electron spin states.
- Its spin states also persist long enough to support computation.
- It emits enough light to be detected.
- Its color remains stable enough to enable entanglement.
Previously, researchers could measure molecular qubits only in groups, averaging their signals rather than reading individual units. To develop the material, NVision screened more than 150 molecules computationally and synthesized 40 candidates in the laboratory. The team embedded a stable precursor within a crystal made of a nearly identical molecule, cooled the system to 4.5 Kelvin, and used laser light to convert the precursor into active qubits. Microwave pulses then extended the qubits’ coherence time — the duration they can retain their quantum state — to 2.2 milliseconds.
Emission-frequency stability is key
The researchers had observed that the molecules’ emission frequencies changed very little over more than an hour of repeated laser excitation. That stability is important because it could allow the qubits to be controlled and linked reliably in future devices.
