Fig. 5

The plot depicts the square of the modulus of the partition function (9) for the 3-spin chain as a function of the \(\alpha\). The two cases presented include \(h=0\) (a) and \(h=J\) (b), where J denotes the coupling constant. The solid lines represent the theoretical predictions, while the dots correspond to the results obtained on the ibm-lagos quantum computer. Fisher zeros are identified at specific points, such as \(J\alpha =2\pi\) and \(6\pi\) for the case with \(h=0\) (a), and \(J\alpha =\pi\), \(2\pi\), \(3\pi\), \(5\pi\), \(6\pi\), \(7\pi\) for the case with \(h=J\) (b). Here we divided the partition function by 8.