Fig. 1: Three-body correlations and symmetry breaking in a quantum dot in the Kondo regime.

a Schematic view of the correlations between the three electrons accounting for the Fermi liquid correction. b Schematic view of the three-body correlation χ_↑↑↓. Electrons fluctuate between the quantum dot (QD) and the leads in the equilibrium and all those processes are summed up in χ_↑↑↓. c (center) QD with the time-reversal symmetry (TRS) and particle-hole symmetry (PHS). The energy level is ε_σ = −U/2. The two-body correlations \({\chi }_{{\sigma }_{1}{\sigma }_{2}}\) are finite, while the three-body correlations are quenched. (left) QD with broken TRS, where the two spins are separated by gμ_BB. (right) QD with broken PHS, where the energy level is ε ≠ −U/2. Experimentally, the gate voltage is applied to the QD in order to tune the energy level. In these broken symmetry cases, the three-body correlations \({\chi }_{{\sigma }_{1}{\sigma }_{2}{\sigma }_{3}}\) are finite, which we detect in this paper.