Novel Fabrication of Quantum Wires: Towards Fractionalized Excitations

The quest for novel quantum states in condensed matter physics often hinges on the reduction of system dimensionality. In particular, one-dimensional systems are theoretically predicted to host a range of fractionalized excitations. These include the Tomonaga-Luttinger liquid, which exhibits spin and charge separation, and the Majorana particle, a cornerstone for fault-tolerant quantum computing. However, fabricating near-perfect one-dimensional quantum wires has been a significant challenge, especially those involving strongly correlated electrons.

In our research, we have developed a novel method to fabricate quantum wires of a Mott insulator on graphite substrates using pulsed-laser deposition, achieving structures such as stripes, junctions, and nanorings. These single-crystalline wires are one unit cell in thickness and precisely two to four unit cells in width, and can extend to several micrometers in length. The spectroscopy measurements along with theoretical calculations reveal the existence of strong electron correlations in this system. Moreover, our findings emphasize the importance of nonequilibrium reaction-diffusion processes in atomic-scale self-organization, opening up exciting avenues for the exploration of exotic fractionalized states in purely one-dimensional quantum wires.