Quantum criticality in ferroelectric-paraelectric heterostructures

Phase transition between ferroelectricity and quantum paraelectricity via non-thermal tuning parameters can lead to quantum critical behaviour and associated emergent phenomena. Ferroelectric quantum critical systems are, however, rare despite the abundance of ferroelectric materials. In this work, we discuss the possibility of achieving tunable quantum paraelectricity in ferroelectric-paraelectric heterostructures, where the quantum temperature - the temperature below which the onset of an effective ferroelectricity is suppressed due to quantum fluctuations - can be tuned by the thickness ratio. This raises the prospect of observing quantum phase transition and a quantum critical region in such systems, with the thickness ratio as the tuning parameter. The quantum critical region also offers unexpected prospects in the field of ferroelectric quantum criticality. Going forward, experiments geared at elucidating if a quantum phase transition is indeed present in the zero-temperature limit in these heterostructures and at extracting the scaling laws that characterize the ferroelectric quantum critical regime will shed more light on this exciting area.