Ge–Sb–Te (GST) alloys lying along the GeTe–Sb2Te3 pseudo‐binary tie line have proven to be among the most auspicious classes of materials for storage applications. Their success is related to the rapid and reversible phase‐change from the crystalline to the amorphous state, whose strongly different optical and electrical properties can be used to encode information. The main technique used to produce phase‐change material (PCM) thin films, both in academia and in industry, is physical vapor deposition (PVD). The layers fabricated by PVD are polycrystalline in the crystalline state. In their Rapid Research Letter on pp. 415–417, Peter Rodenbach et al. demonstrate the successful molecular beam epitaxy (MBE) of PCM thin films in the quasi‐binary GeTe–Sb2Te3 system on slightly (GaSb) as well as largely (Si) lattice‐mismatched substrates with (111) orientation. MBE growth is anticipated to allow the control …