Sound-driven single-electron transfer in a circuit of coupled quantum rails

Abstract

Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits.

Quantum teleportation of single-electron states

“…Relying on mature semiconducting technology, electronic circuits provide a promising avenue for quantum technologies due to their potential for scalability and integration with existing devices. Motivated by recent progress in the generation and manipulation of single-electron states in mesoscopic systems, a field referred to as electron quantum optics [22][23][24][25][26][27], we propose a scheme for performing quantum teleportation of single-electron states. The scheme is based on electronic analogs of optical components such as beamsplitters and phase shifters to manipulate electrons in a dual-rail qubit configuration, which consists of two spatial modes that an electron can occupy.…”

Phase-Coherent Dynamics of Quantum Devices with Local Interactions

“…Inset—Working principle of the device: A gate voltage controls the orbital energy of the quantum dot, which is filled by the left superconductor and emptied in the right one. ( c ) Long-range single-electron transfer via a radio-frequency pulse between two distant quantum dots QD1 and QD2 [ 14 , 15 , 16 , 17 ]. The electron “surfs” along the moving potential generated by the radio-frequency source and is transferred along a one-dimensional channel from QD1 to QD2.…”

“…Beyond theoretical interest, this question is important for ongoing experiments with mesoscopic devices aimed towards the full control of single electrons out of equilibrium. Figure 1 reports some of these experiments [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ], in addition to the mesoscopic capacitor [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ], which will be extensively discussed in this review. These experiments and significant others [ 27 , 28 , 29 , 30 , 31 , 32 , 33 ] have a common working principle: A fast [ 34 ] time-dependent voltage drive , applied either on metallic or gating contacts, triggers emission of well defined electronic excitations.…”

Entanglement generation via power-of-swap operations between dynamic electron-spin qubits

“…To ensure parameter realism, we calculate the potential profile of the heterostructure with voltages applied to the metallic gates. We use a Poisson-Schrödinger self-consisted solver to calculate the range of values that are possible with current semiconductor technologies [20]. Since this work demonstrates a proofof-concept for the SAW-driven entangling operation, we use analytical equations to reproduce the potentials calculated by our solver.…”