In a one-dimensional (1D) system of interacting electrons, excitations of spin and charge travel at different speeds, according to the theory of a Tomonaga-Luttinger liquid (TLL) at low energies. However, the clear observation of this spin-charge separation is an ongoing challenge experimentally. We have fabricated an electrostatically gated 1D system in which we observe spin-charge separation and also the predicted power-law suppression of tunneling into the 1D system. The spin-charge separation persists even beyond the low-energy regime where the TLL approximation should hold. TLL effects should therefore also be important in similar, but shorter, electrostatically gated wires, where interaction effects are being studied extensively worldwide.
Basically, this study cooled down a string of electrons (tunneling) to near absolute zero (0 K or very very cold), packed the electrons extremely close together and observed the results.
The electrons broke down into two (new) particles, holons and spinons.
When our children are adults, they’ll be working with quantum computers and looking back on this type of research like we look back on the computer science of the 50’s. Plus, this is incredible science.