Hybrid light-matter particles developed by FLEET researchers solve the circuit heating problem that is driving up electricity consumption in computer devices.
Modern transistors on chips in computer devices are not energy efficient. As electrons move through these circuits, interaction with the materials in the circuit generates heat. All circuits currently in production have an intrinsic resistance and generate heat when current flows through them.
A substantial amount of the energy used by computers is wasted because the electricity used to power the circuits heats up the device as it performs its tasks. Not to mention the energy needed to combat this heating.
Although we barely notice the heating of our individual devices anymore, traditional data-server centres, cryptocurrency farms and AI data centres generate significant amounts of heat. These facilities produce enough heat that they can generate their own microclimates, contributing to global warming regardless of whether the power source is renewable.
ARC CoE Future Low Energy Electronic Technologies (FLEET) researchers at Monash University and the Australian National University, led by Chief Investigator Elena Ostrovskaya, are investigating polariton superfluids, a phase of matter that allows current to flow without generating heat, as potential next gen transistors.
Polaritons are hybrid particles formed of light and matter that are strong candidates for the realisation of near-zero resistance technology.
A polariton is formed when a photon is strongly coupled with an electric dipole that is free to move through a non-metallic material. In semiconductors, a dipole is created by the movement of electrons from the material into the electric circuit, leaving behind a positive ‘hole’. The combination of the electron-hole pair is called an exciton. In essence, these photon– exciton hybrid particles possess properties of both light, in having little mass, and matter, with the ability to interact with other particles.
Superfluidity, most usually observed in helium cooled to temperatures near absolute zero (-273 °C), has been a property exhibited only at incredibly cold temperatures.
Other materials can also exhibit superfluidity; however, cryogenic cooling is necessary to achieve near-zero resistance.
Incredibly, exciton-polaritons can form superfluids at room temperatures, which enables them to spread through a material with negligible resistance. As a result, polariton technology can be utilised in next-generation circuits to prevent circuit-based heating.
Polaritons could be a new class of information carriers that can transport data in computers.
Previous attempts at forming polariton superfluids were complex and costly. However, Dr Mitko Oldfield’s research at FLEET has focused on forming polaritons in perovskite semiconductor films that are easy-to-make, cost-effective and readily create excitons when the material is exposed to light.
With assistance from our ANFF-ACT facility, Dr Oldfield successfully sandwiched the anatomically thin semiconductor between 2 Bragg reflector mirrors, creating an optical microcavity system with remarkable stability.
Lasing of the microcavities resulted in strong exciton–photon coupling, achieving a superfluid state. This material shows great promise for both fundamental and applied room-temperature polaritonics.
Due to their semiconductor nature, polaritonic devices could be readily integrated into conventional electronic circuits. Future applications include using polaritons in anatomically thin semiconductors to enable near-zero resistance, ultra-low energy electronic devices.
Pushing the frontiers of transistor materials is part of the global effort to develop low-energy semiconductor technologies for computing and information processing.
Published 15 October 2024 in ANFF’s 2024 Casebook ‘ANFF NEXT‘
Posted 23 May 2025
