const J = 1, h = 1, dt = Math.PI / 8;
const c = circuit(2);
// e^{-i*(-J)*dt*ZZ} = e^{i*J*dt*ZZ}, theta = -J*dt in e^{-i*theta*ZZ}
// e^{-i*theta*ZZ}: cx(0,1), rz(2*theta, 1), cx(0,1)
// With theta = -J*dt = -pi/8:
c.cx(0, 1);
c.rz(-2 * J * dt, 1);
c.cx(0, 1);
// e^{-i*(-h)*dt*X} = e^{i*h*dt*X}, theta = -h*dt in e^{-i*theta*X} = rx(2*theta, q)
c.rx(-2 * h * dt, 0);
c.rx(-2 * h * dt, 1);
return c;