Fig. 2: The Zitterbewegung effect.
From: Experimental simulation of Dirac equation in superconducting qubits
a Illustration of Zitterbewegung in momentum space, the rapid oscillation between eigenstates with opposite eigenvalues. b–d Demonstrations of velocities in the x and y directions with three different masses with dots(Experimental results) and dashed lines(numerical simulation). The frequency of oscillation in the x and y directions can be observed, with momentum \({{{{\bf{p}}}}}=(1.3/\sqrt{2}\,\,{\mbox{MHz}}\,,1.3/\sqrt{2}\,\,{\mbox{MHz}}\,,0)\). e The oscillation frequency of velocities increases with the mass. Measured velocities with different momentum, p = (1.3 MHz, 0, 0) for (f) and \({{{{\bf{p}}}}}=(1.3/\sqrt{2}\,\,{\mbox{MHz}}\,,-1.3/\sqrt{2}\,\,{\mbox{MHz}}\,,0)\) for (g).
