Plate Nº 29 · recorded November 10, 2026
Chemistry & MaterialsReported finding
Perovskite quantum wells hold spins 300 times longer at room temperature
An HKUST team built a chiral perovskite quantum-well stack that keeps electron spins polarized for about 5 nanoseconds at room temperature, roughly 300 times longer than before.
By Priya Raman4 min read711 words
In brief
- Spin polarization persists for approximately 5 nanoseconds at room temperature, about 300 times longer than in previous systems.
- Circularly polarized luminescence reached a luminescence dissymmetry factor (gₗᵤₘ) of up to 1.4 × 10⁻².
- Spin-dependent charge transport showed a polarization degree exceeding 80%.
- The stack was grown by a two-step seed-assisted crystallization method spanning 2D (n = 1), quasi-2D (n = 2, 3, 4, …) and 3D (n = ∞) perovskite phases.
- Published as Jian Qiu et al., Nature Photonics (2026), DOI: 10.1038/s41566-026-02027-6.
A chiral perovskite system keeps electron spins polarized at room temperature for roughly 300 times longer than previous designs, lifting the spin lifetime to about 5 nanoseconds. Lu Haipeng, a professor in the Department of Chemistry at The Hong Kong University of Science and Technology (HKUST), led the work, published in Nature Photonics in 2026 by Jian Qiu and colleagues.
Spin-based electronics promises faster processing at lower power than the semiconductors that already underpin modern optoelectronic devices, an industry still squeezed on both speed and energy consumption. The obstacle has been thermal. Spin decoherence — the rapid loss of spin alignment inside a material — destroys the signal almost as soon as room-temperature noise arrives, and long-lived spin polarization has typically been achievable only at ultralow temperatures.
What did the team actually build?
The HKUST group assembled a perovskite chiral multiple quantum-well system: a stack of thin semiconductor layers, each narrow enough to confine electrons in two dimensions, so that each layer behaves as a discrete energy step rather than a continuous band.
They grew that stack using a two-step seed-assisted crystallization approach, in which crystals are nucleated in a controlled first step and then grown onward in a second. The result produced well-oriented quantum wells of varying widths sharing continuous intrinsic chirality — a structural handedness that cannot be superimposed on its own mirror image — across three families of perovskite phase:
- two-dimensional (n = 1)
- quasi-two-dimensional (n = 2, 3, 4, …)
- three-dimensional (n = ∞)
How does the spin cascade work?
The structurally coupled wells establish an energy gradient and a fully chiral environment, generating a series of intermediate spin-polarized states. The architecture functions like a nested staircase of energy steps, each one lower than the last, so that spin information can be handed down the stack rather than scattered away at every boundary. Because the layers are structurally coupled, interfacial spin losses fall, and spin relaxation within the bulk phases is suppressed.
Lu Haipeng said: "Our study demonstrates that introducing intrinsic chirality across successive quantum-well phases, together with a graded energy landscape, enables efficient spin transfer and prolonged spin polarization in perovskite semiconductors. This provides a promising platform for spin accumulation and the development of advanced chiroptical and spintronic devices."
What did the material measure?
The team's report lists three quantified results:
- Spin polarization persisting for approximately 5 nanoseconds at room temperature, about 300 times the conventional figure, against a background in which such lifetimes generally required ultralow temperatures.
- Circularly polarized luminescence — light emitted with a preferred handedness — reaching a luminescence dissymmetry factor (gₗᵤₘ, the degree to which the emitted light favours one handedness over the other) of up to 1.4 × 10⁻².
- Spin-dependent charge transport with a polarization degree exceeding 80%, meaning most of the moving charge in the device carries a net spin preference.
What can it be used for?
Building on those properties, the team developed proof-of-concept applications:
- X-ray-triggered dissymmetric photopolymerization, in which the material's spin-polarized output drives a chemical reaction whose products prefer one handedness.
- High-performance circularly polarized light detection, a device class that measures the handedness of incoming light.
The authors point to asymmetric photocatalysis — reactions driven preferentially by one handedness of light — and to advanced optical sensing as the downstream targets.
What remains unproven?
Both demonstrations remain at proof-of-concept stage, and the release describes no complete device architecture, no operating lifetime, and no comparison against a named state-of-the-art spin-polarized emitter. Nor does it give the baseline spin lifetimes behind the 300-fold improvement, so the size of the gain cannot be checked against a specific prior system. The claims are also structural rather than electrical: the advance lies in the coupled, chiral layer design, not in a new transport mechanism. Lu's own framing is cautious, describing a "promising platform" rather than a finished technology.
The open question is whether a 5-nanosecond window of room-temperature spin survival can be extended, and chained, into a signal that survives contact with real circuitry.
Publication: Jian Qiu et al., "Perovskite chiral multiple quantum wells with extended spin lifetime via efficient spin cascade," Nature Photonics (2026). DOI: 10.1038/s41566-026-02027-6.
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Senior reporter covering people, launches and day-to-day practice in general science news at SciBeat.
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