Interplanetary Communication: Scientists Transfer Electron Spin to Photons

Scientists, including Igor Zutic from the University at Buffalo and Yuan Lu from France’s Jean Lamour Institute, have made a breakthrough in quantum technology by transferring electron spin to photons. This could revolutionize long-distance optical telecommunications, including communication between Earth and Mars.

The method operates at room temperature, doesn’t require a magnetic field, and allows for electrical control. This advancement could lead to ultrafast communication and quantum technologies. The research was supported by the National Science Foundation and the U.S. Department of Energy, and involved contributors from France, Germany, Japan, China, and the United States.

Quantum Tech Advancement: Electron Spin to Photons Transfer

Scientists have made a significant breakthrough in the field of spintronics, a technology that manipulates the spin of electrons to store and process information. The researchers have successfully transferred spin information from electrons to photons, the particles that constitute light. This discovery could revolutionize long-distance optical telecommunications, including communication between Earth and Mars.

The method developed by the researchers meets three crucial criteria: operation at room temperature, no need for a magnetic field, and the ability for electrical control. This opens up a range of applications, including ultrafast communication and quantum technologies. The research was supported by the National Science Foundation’s Electronics, Photonics and Magnetic Devices (EPMD) program and the U.S. Department of Energy’s Basic Energy Sciences (BES) program.

Spintronics: A Potential Replacement for Conventional Electronics

Spintronics has been successfully used in magnetic computer hard drives, where information is represented by electron spin and, by its proxy, the direction of magnetization. Ferromagnets, such as iron or cobalt, have an unequal number of electrons whose spins are oriented either along or against the magnetization axis. This represents binary information, 0 and 1.

Spintronic devices, whose magnetic state can be considered as stored information, is maintained indefinitely. This makes them much more power-efficient than conventional electronics. However, the spin information is quickly lost and cannot travel far when electrons are taken out of the ferromagnet. This major limitation can be overcome by utilizing light through its circular polarization, helicity, as another spin carrier.

Spin-LEDs: Meeting Crucial Criteria for Practical Application

The concept of spin-LEDs was initially proposed at the end of the last century. However, for the transition into a practical application, it must meet three crucial criteria: operation at room temperature, no need of magnetic field, and the ability for electrical control. The collaborative team has conquered all obstacles after more than 15 years of dedicated work in this field.

The researchers successfully switched the magnetization of a spin injector by an electrical pulse using the spin-orbit torque. The electron’s spin is rapidly converted into information contained in the helicity of the emitted photons, enabling a seamless integration of magnetization dynamics with photonic technologies.

Future Applications: From Interplanetary Communication to Quantum Technologies

This electrically controlled spin-photon conversion is now achieved in the electroluminescence of light-emitting diodes. In the future, through the implementation in semiconductor laser diodes, so-called spin-lasers, this highly-efficient information encoding could pave the way for rapid communication over interplanetary distances since polarization of light can be conserved in space propagation, potentially making it the fastest mode of communication between Earth and Mars.

Moreover, it will also greatly benefit the development of various advanced technologies on Earth, such as optical quantum communication and computation, neuromorphic computing for artificial intelligence, ultrafast and highly-efficient optical transmitters for data centers or Light-Fidelity (LiFi) applications. The realization of spin-orbit-torque spin injectors is a decisive step that will greatly advance the development of ultrafast and energy-efficient spin-lasers for the next generation of optical communication and quantum technologies.