The need for decarbonization of the heat supply has led to increased attention to heat pump technology. When analysing endogenous exergy losses of the Rankine heat pump cycles, it becomes obvious that the expansion losses due to the isenthalpic pressure reduction, have a significant effect, especially for higher temperature lifts. For the first time, this publication presents the heat pump cycle of a novel thermodynamic cycle concept called Recuperative Two-Phase Cycle (RTPC), which intents to reduce these expansion losses using an internal heat exchanger, where an evaporation takes place on the low-pressure side. It is made possible by a non-linear zeotropic mixture composed of a main and an auxiliary working fluid. During the heat rejection to the heat sink, the temperature can have a glide or be nearly constant. In the case of isothermal conditions, the cycle resembles an ideal Ericsson cycle. In this work, the concept is derived from the state-of-the-art, different ideal cycle configurations and the theoretical challenges for a technical realization are presented. Furthermore, a description for a basic calculation is given and the potential for heat pump applications is illustrated by the study case of a heat pump with a temperature lift of 85 K between a latent heat source and sink. The endoreversible cycle approximating the shape of an ideal Ericsson cycle reaches a second law efficiency of 81.3 %, because the expansion losses can be reduced to 2.9 %.