Modeling and Simulations of Solid-state Devices for Quantum Technologies

Designing devices to perform logic operations for quantum information/communication requires the ability to model and simulate the quantum evolutions of the qubits including the complexities of the realistic devices which may introduce several unwanted effects.

The group has a strong tradition in theoretical and numerical modelling of quantum states and transport of correlated charges in semiconductor nanodevices. Such studies involve both theoretical developments and High-Performance-Computing techniques. Two examples are shown in the figures. In the top panel two electron wavepackets are travelling in an electron interferometer from sources S1, S2 to detectors D1, D2, interacting in the central region.  In the bottom panel, an exciton –a Coulomb interacting electron-hole pair- wavepacket (green) bounces off an anti-dot, a repulsive potential region for the electron (blue) in a so-called excitronic device. The complex correlated motion of the two particles produces a scattered wavepacket resembling a diffraction pattern (where no slit is present, though).

Realistic devices are negatively influenced by phase disruption, due to a variety of mechanisms. In this respect, quantum walks methods are used by the group to understand their influence on the unitary evolution in logic gates.

Long lived spin excitations may encode quantum information and may serve e.g. in Majorana-fermions-based quantum hardware. Such excitations strongly depend on (and can be manipulated by) device engineering. Such aspects are theoretically investigated by k.p theories in collaborations with partner experimental groups.

Images adapted from Phys. Rev. B 99, 245415 (2019) and Superlattices and Microstructures 108, 73 (2017).

 

People: Prof. G. Goldoni; Dr. P. Bordone; Dr. A. Bertoni (CNR).

[Ultimo aggiornamento: 04/02/2021 10:35:53]