Imagine a world where quantum devices don’t need to hide inside bulky refrigerators colder than outer space. For decades, this has been the biggest roadblock as quantum states vanish unless they are locked in crystals or machines frozen near absolute zero.
This makes quantum applications impractical for real-world use. Interestingly, a team of researchers from Georgia Institute of Technology and the University of Alabama has found a solution to this problem.
They have developed a new type of polymer, a plastic-like material, that can hold and manipulate quantum states in solid form at room temperature. This achievement could change the way we think about building future quantum devices, bringing them out of extreme lab environments and into everyday use.
Achieving the quantum impossible
For developing a room-temperature quantum material, instead of using rigid crystals like diamond or silicon carbide, the researchers turned to chemistry for answers. They designed a conjugated polymer, a long molecular chain made up of alternating building blocks that conduct electrons.
One of the blocks was a donor unit based on an organic compound called dithienosilole, and the other was an acceptor unit called thiadiazoloquinoxaline. Together, these units created the right conditions for unpaired electron spins to move along the backbone of the polymer without quickly losing their quantum information.
They placed a silicon atom at the heart of the donor unit. This caused the polymer chain to twist slightly, which prevented the chains from stacking too tightly. Normally, close stacking makes spins interact too strongly, wiping out their delicate quantum states. However, here, the twist reduced those harmful interactions while still allowing electrons to communicate along the chain.
Next, to make the polymer processable, the researchers attached long hydrocarbon side chains. These side chains kept the molecules from clumping together, ensured the material dissolved easily, and helped maintain electronic coherence across the chain. The researchers then used a mix of theoretical modeling and experiments to confirm that their design worked.
Simulations showed that as the polymer chain grew longer, the spin density spread out across it. Eventually, the system settled into a high-spin ground state, a low-energy arrangement with two unpaired electrons aligned in the same direction. This type of state is similar to those used in solid-state qubits.
Experimental verification of the material
To validate the results from their simulations in the lab, the researchers first ran magnetometry tests. These showed that the material’s spins behaved as if there were two unpaired electrons aligned in the same direction, a state known as a triplet ground state.
They then used a technique called electron paramagnetic resonance (EPR) spectroscopy. In simple terms, EPR works a bit like MRI but for electrons. It uses microwaves and a magnetic field to catch the tiny magnetic signals of unpaired electrons.
The results showed narrow and symmetric signals, which is a good sign because it means the spins are behaving in an orderly way. The researchers also measured the g-factor, a number that tells how strongly an electron responds to a magnetic field.
For a perfectly free electron, the g-factor is about 2.0. The polymer’s g-factor was very close to this value, which means the electrons were not heavily disturbed by their surroundings. This low level of disturbance, called low spin–orbit coupling, helps the quantum states stay stable for longer.
However, the real breakthrough came when they measured how long the spins could remain stable. At room temperature, the polymer’s spin-lattice relaxation time (T1) was about 44 microseconds, and its phase memory time (Tm) was 0.3 microseconds. These values are already better than many other molecular systems.
When cooled to 5.5 kelvin, T1 jumped to 44 milliseconds and Tm stretched to more than 1.5 microseconds. Most importantly, these results were achieved without embedding the material in frozen solvents or isolating it in special matrices, conditions that usually make molecular systems impractical for real-world devices.
The team also showed that the polymer could undergo Rabi oscillations, a sign of controlled quantum operations. By applying microwave pulses, they could predictably flip the spin states, essentially performing the basic actions needed for quantum computing.
Finally, they demonstrated that this polymer isn’t just a lab gimmick. It can be made into thin films, works as a p-type semiconductor in transistors, and operates stably under repeated use. This means it can be integrated into electronic devices, combining both charge and spin functions.
An important step for making quantum applications practical
This discovery is significant because it shows that quantum materials don’t have to be fragile crystals trapped in cryogenic chambers. Instead, they can be flexible, tunable, and processable polymers that still support quantum coherence.
“This work demonstrates a fundamentally new approach toward practically applicable organic, high-spin qubits that enable coherent control in the solid-state,” the study authors note.
Such materials could open the door to practical quantum sensors that work in everyday conditions, thin-film devices that combine classical electronics with quantum capabilities, and scalable platforms for exploring quantum computing.
However, this innovation doesn’t solve all the challenges associated with quantum computing. For instance, the phase memory time (duration up to which quantum states are in sync) at room temperature is still relatively short compared to what’s needed for large-scale quantum computing.
The researchers now plan to further optimize the structure, test new donor-acceptor combinations, and explore device architectures where electronic and spin functions can work together.
The study is published in the journal Advanced Materials.