Quantum effects in memristive devices

Quantum conductance phenomena in semiconductors and metals. a) Schematic representation of a semiconductor-based device showing conductance quantization, where a 2DEG is formed at the interface of a heterojunction. The quantum point contact is achieved by applying a negative voltage to the gate electrodes while measuring the transport properties through the contacts to the 2DEG on either side of the constriction. The constriction width (W) can be changed by means of the applied gate voltage. b) Schematic representation of a metal-based device where the quantization of conductance can be observed when the metal contact is of atomic dimensions. Credit: Gianluca Milano et al, Advanced materials (2022). DOI: 10.1002/adma.202201248

At the nanometric scale, the laws of classical physics suddenly become insufficient to explain the behavior of matter. It is precisely at this moment that quantum theory comes into play, effectively describing the physical phenomena characteristic of the atomic and subatomic world. Thanks to the different behavior of matter at these length and energy scales, it is possible to develop new materials, devices and technologies based on quantum effects, which could give rise to a real quantum revolution that promises to innovate in fields such as cryptography, telecommunications and computing.

The physics of very small objects, already the basis of many technologies that we use today, is intrinsically linked to the world of nanotechnology, the branch of applied sciences dealing with the control of matter at the nanometer scale (a nanometer is one billionth of a meter). This control of matter at the nanoscale is the basis for the development of new electronic devices.

Among these, memristors are considered promising devices for the realization of new computing architectures emulating the functions of our brain, allowing the creation of increasingly efficient computing systems suitable for the development of the entire artificial intelligence, as recently demonstrated by the Istituto Nazionale di Ricerca Metrologica (INRiM researchers) in collaboration with several universities and international research institutes.

In this context, the EMPIR MEMQuD project, coordinated by INRiM, aims to study quantum effects in such devices, in which electronic conduction properties can be manipulated to allow the observation of quantified conductivity phenomena at room temperature. In addition to analyzing fundamentals and recent developments, the summary work “Quantum Conductance in Memristive Devices: Fundamentals, Developments, and Applications” recently published in the journal Advanced materialsanalyzes how these effects can be used for a wide range of applications, from metrology to next-generation memory development and artificial intelligence.

Provided by INRIM – National Institute for Metrological Research