Electric machine which has a winding system group comprising at least two stator winding systems (121, 121') and a rotor arrangement with at least two rotors (110, 110'), wherein - each rotor (110, 110') of the rotor arrangement comprises at least one permanent magnet (111, 111') as a magnetic means, - each rotor (110, 110') of the rotor arrangement is assigned to a stator winding system (121, 121') of the winding system group and is rotatable relative to the stator winding system (121, 121') assigned thereto, - each stator winding system (121, 121') of the winding system group and the rotor (110, 110'), assigned to the respective stator winding system (121, 121'), of the rotor arrangement are designed in such a way, and arranged so as to form a respective air gap (113, 113') between one another, that they can interact electromagnetically with one another, characterized in that - the electric machine has a demagnetization device with which, in the event of a fault in a faulty stator winding system (121, 121') of the winding system group, a targeted demagnetization of the magnetic means (111, 111') of the rotor (110, 110') assigned to the faulty stator winding system (121, 121') can be carried out, wherein the demagnetization device has a heating apparatus, wherein - the heating apparatus for each rotor (110, 110') of the rotor arrangement has a heating-up device (321, 322) assigned to the respective rotor (110, 110'), wherein each heating-up device (321, 322) is separately activatable and deactivatable and set up and arranged in order, after activation, to separately heat up only that rotor (110, 110'), and in particular the magnetic means (111, 111') thereof, to which the activated heating-up device (321, 322) is assigned, - the demagnetization device is set up in order, if necessary, in particular in the event of a fault, and in a targeted manner, to be able to activate each heating-up device (321, 322) separately, wherein the heating apparatus comprises a configurable fluid connection to a heat source, wherein - heat can be conducted from the heat source to the electric machine via the fluid connection, - the fluid connection for each rotor (110, 110') of the rotor arrangement has a line (325, 326) assigned to the respective rotor (110, 110') for guiding the heat from the heat source to the respective rotor (110, 110'), wherein the respective line (325, 326) is part of the heating-up device (321, 322) assigned to the respective rotor (110, 110'), - the demagnetization device is set up to configure the fluid connection in such a way that the heat is guided only to that rotor (110, 110') which is assigned to the faulty stator winding system (121, 121'). - each rotor (110, 110') of the rotor arrangement comprises at least one permanent magnet (111, 111') as a magnetic means, - each rotor (110, 110') of the rotor arrangement is assigned to a stator winding system (121, 121') of the winding system group and is rotatable relative to the stator winding system (121, 121') assigned thereto, - each stator winding system (121, 121') of the winding system group and the rotor (110, 110'), assigned to the respective stator winding system (121, 121'), of the rotor arrangement are designed in such a way, and arranged so as to form a respective air gap (113, 113') between one another, that they can interact electromagnetically with one another, characterized in that - the electric machine has a demagnetization device with which, in the event of a fault in a faulty stator winding system (121, 121') of the winding system group, a targeted demagnetization of the magnetic means (111, 111') of the rotor (110, 110') assigned to the faulty stator winding system (121, 121') can be carried out, wherein the demagnetization device has a heating apparatus, wherein - the heating apparatus for each rotor (110, 110') of the rotor arrangement has a heating-up device (321, 322) assigned to the respective rotor (110, 110'), wherein each heating-up device (321, 322) is separately activatable and deactivatable and set up and arranged in order, after activation, to separately heat up only that rotor (110, 110'), and in particular the magnetic means (111, 111') thereof, to which the activated heating-up device (321, 322) is assigned, - the demagnetization device is set up in order, if necessary, in particular in the event of a fault, and in a targeted manner, to be able to activate each heating-up device (321, 322) separately, wherein the heating apparatus comprises a configurable fluid connection to a heat source, wherein - heat can be conducted from the heat source to the electric machine via the fluid connection, - the fluid connection for each rotor (110, 110') of the rotor arrangement has a line (325, 326) assigned to the respective rotor (110, 110') for guiding the heat from the heat source to the respective rotor (110, 110'), wherein the respective line (325, 326) is part of the heating-up device (321, 322) assigned to the respective rotor (110, 110'), - the demagnetization device is set up to configure the fluid connection in such a way that the heat is guided only to that rotor (110, 110') which is assigned to the faulty stator winding system (121, 121').