A requirement for quantum information processors is the in situ tunability of the tunnel rates and the exchange interaction energy within the device. The large energy level separation for atom qubits in silicon is well suited for qubit operation but limits device tunability using in-plane gate architectures, requiring vertically separated top-gates to control tunnelling within the device. In this paper, we address control of the simplest tunnelling device in Si:P, the tunnel junction. Here we demonstrate that we can tune its conductance by using a vertically separated top-gate aligned with ±5 nm precision to the junction. We show that a monolithic 3D epitaxial top-gate increases the capacitive coupling by a factor of 3 compared to in-plane gates, resulting in a tunnel barrier height tunability of 0-186 meV. By combining multiple gated junctions in series we extend our monolithic 3D gating technology to implement nanoscale logic circuits including AND and OR gates.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.nanolett.1c03879 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
An ultra-high vacuum scanning tunneling microscope with pulse tube and Joule-Thomson cooling operating at sub-pm z-noise.
Rev Sci Instrum
December 2024
2nd Institute of Physics B and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany.
Low-temperature scanning tunneling spectroscopy is a key method to probe electronic and magnetic properties down to the atomic scale, but suffers from extreme vibrational sensitivity. This makes it challenging to employ closed-cycle cooling with its required pulse-type vibrational excitations, albeit this is mandatory to avoid helium losses for counteracting the continuously raising helium prices. Here, we describe a compact ultra-high vacuum scanning tunneling microscope (STM) system with an integrated primary pulse tube cooler (PTC) for closed-cycle operation.
View Article and Find Full Text PDFUnraveling the Interplay Between Memristive and Magnetoresistive Behaviors in LaCoO/SrTiO Superlattice-Based Neural Synaptic Devices.
Small Methods
December 2024
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, China.
Memristors and magnetic tunnel junctions are showing great potential in data storage and computing applications. A magnetoelectrically coupled memristor utilizing electron spin and electric field-induced ion migration can facilitate their operation, uncover new phenomena, and expand applications. In this study, devices consisting of Pt/(LaCoO/SrTiO)/LaCoO/Nb:SrTiO (Pt/(LCO/STO)/LCO/NSTO) are engineered using pulsed laser deposition to form the LCO/STO superlattice layer, with Pt and NSTO serving as the top and bottom electrodes, respectively.
View Article and Find Full Text PDFMinimal Models and Transport Properties of Unconventional p-Wave Magnets.
Phys Rev Lett
December 2024
Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
New unconventional compensated magnets with a p-wave spin polarization protected by a composite time-reversal translation symmetry have been proposed in the wake of altermagnets. To facilitate the experimental discovery and applications of these unconventional magnets, we construct an effective analytical model. The effective model is based on a minimal tight-binding model for unconventional p-wave magnets that clarifies the relation to other magnets with p-wave spin-polarized bands.
View Article and Find Full Text PDFEnhanced Synaptic Memory Window and Linearity in Planar InSe Ferroelectric Junctions.
Adv Mater
December 2024
Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
A synaptic memristor using 2D ferroelectric junctions is a promising candidate for future neuromorphic computing with ultra-low power consumption, parallel computing, and adaptive scalable computing technologies. However, its utilization is restricted due to the limited operational voltage memory window and low on/off current (I) ratio of the memristor devices. Here, it is demonstrated that synaptic operations of 2D InSe ferroelectric junctions in a planar memristor architecture can reach a voltage memory window as high as 16 V (±8 V) and I ratio of 10, significantly higher than the current literature values.
View Article and Find Full Text PDFRevealing Single-Molecule Photocurrent Generation Mechanisms under On- and Off-Resonance Excitation.
Nano Lett
December 2024
Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
We investigate photocurrent generation mechanisms in a pentacene single-molecule junction using subnanometer resolved photocurrent imaging under both on- and off-resonance laser excitation. By employing a wavelength-tunable laser combined with a lock-in technique, net photocurrent signals are extracted to elucidate photoinduced electron tunneling processes. Under off-resonance excitation, photocurrents are found to arise from photon-assisted tunneling, with contributions from three distinct frontier molecular orbitals at different bias voltages.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!