A group of scientists has created a quantum material where electricity can flow without losing energy as heat. Until now, this was only seen in superconductors, but with many limitations. This advance opens the door to more efficient and more stable devices that require less cooling. So, let’s learn more about this, shall we?
Why does electricity normally lose energy?
When we use electricity in our electronic devices, part of that energy is always transformed into heat. This happens in every cable and device, and causes several issues:
- Devices heat up and need cooling systems.
- Energy is wasted, lowering efficiency.
- It limits the performance of modern technology, from computers to smartphones.
Physicists have been trying to find a way to make electricity flow without producing heat, meaning no energy loss.
From the Hall effect to the fractional quantum Hall effect
To understand this discovery we first need to know a phenomenon called the Hall effect: If you place a material in a magnetic field, electricity generates a sideways voltage. In very thin materials at very low temperatures, this becomes the quantum Hall effect, where conductivity occurs in perfectly defined steps.
Then, we have the fractional quantum Hall effect, which is even more amazing: Here, electrons stop acting as independent particles and act collectively, which makes it seem as if electrons are divided into fractions of charge (though they do not physically split). These properties are very stable, making devices using them more resistant to interference.
Quantum material without dissipation
The researchers published this finding in Nature Physics, showing the first observation of a dissipation-free fractional Chern insulator. Basically, it’s a material where electric current flows only along the edges without turning into heat. This confirms a theory proposed more than ten years ago and opens the path to more efficient quantum technologies.
But, do you know something incredible about these materials? They have special properties called topological properties, which make them extremely resistant to external disturbances.
Fractional Chern insulator and electricity with no heat
This discovery is based on a concept called fractional Chern insulator, a material capable of allowing electric current to flow without energy dissipation. Before, quantum Hall effects required very intense magnetics fields, but this material can replicate the effect without the need of external fields. In 2023, a similar effect had been already observed, known as the fractional anomalous quantum Hall effect, but there was still longitudinal resistance, meaning some electricity was lost as heat.
The recent breakthrough eliminated this problem using two key techniques:
- Making the crystals better: This lets the electrons move more smoothly, like cars driving on a highway with no bumps or traffic.
- Carefully lining up the layers of the material: Tiny misalignments can block the flow of electricity, so adjusting the layers makes the electrons travel freely along the edges.
The result: electricity flows along the edges without measurable energy loss, achieving for the first time a truly dissipation-free fractional Chern insulator.
Additional discoveries
The scientists also studied the thermal activation gap, the energy needed for electrons to move to excited states. They found the gap decreases with increasing magnetic field and then stabilizes. This shows that fractional Chern insulators have more complex physics than previously thought, involving different low-energy excitations linked to electron spin and charge.
So, imagine a world where your devices don’t overheat, computers run more efficiently, and advanced quantum technologies become practical for everyday use. That future is a step closer thanks to the discovery of a dissipation-free fractional Chern insulator, a material where electricity flows without losing energy as heat.