const J = 1.0, h = 1.0, t = 0.3;
const tzz = 2 * J * t, tx = 2 * h * t;
const c = circuit(3);
// ZZ interaction on the two bonds of the open chain
c.cx(0, 1); c.rz(tzz, 1); c.cx(0, 1);
c.cx(1, 2); c.rz(tzz, 2); c.cx(1, 2);
// transverse field on every qubit
c.rx(tx, 0);
c.rx(tx, 1);
c.rx(tx, 2);
c.measure();
return c;