In a significant stride for quantum technologies, a team of researchers from various institutions, including the University of Bayreuth in Germany and ETH Zurich in Switzerland, has uncovered exceptionally long spin coherence times in a type of semiconductor known as perovskites. This discovery, published in the journal Nature Communications, opens up new possibilities for the energy sector, particularly in the development of quantum devices with all-optical control.
The researchers focused on a specific type of perovskite, a lead halide perovskite crystal with the composition FA0.95Cs0.05PbI3. They found that this material exhibits an electron spin coherence time (T2) of the order of 1 millisecond, which is remarkably long for a bulk crystal. Spin coherence time refers to the duration over which the spin states of electrons remain synchronized, a crucial factor for implementing quantum technologies.
To achieve this, the team used a technique called spin mode locking, where periodic laser pulses synchronize the electron spin Larmor precession about an external magnetic field. This process results in a decay of the optically created ensemble spin polarization within a dephasing time (T2*) of up to 20 nanoseconds and its revival during the spin coherence time (T2) reaching the millisecond range.
The long spin coherence time in this bulk crystal is complemented by millisecond-long longitudinal spin relaxation times (T1) for both electrons and holes, measured by optically-detected magnetic resonance. These findings highlight perovskites as a promising platform for quantum devices with all-optical control.
For the energy sector, this research could pave the way for more efficient and advanced quantum devices, such as quantum sensors and quantum computers, which could revolutionize energy management and optimization. The ability to control and manipulate spin states with optical methods could also lead to advancements in spintronics, a field that combines electronics and magnetism, potentially leading to more energy-efficient electronic devices.
In summary, the discovery of millisecond spin coherence times in semiconducting perovskites represents a significant step forward in the development of quantum technologies. The practical applications for the energy sector are vast, promising more efficient and advanced devices that could transform energy management and optimization.
This article is based on research available at arXiv.