Bulletin of the American Physical Society
APS March Meeting 2022
Volume 67, Number 3
Monday–Friday, March 14–18, 2022; Chicago
Session B12: Ballistic Transport in Semiconductor DevicesRecordings Available
|
Hide Abstracts |
Sponsoring Units: FIAP Chair: Giti Khodaparast, FIAP Room: McCormick Place W-181C |
Monday, March 14, 2022 11:30AM - 11:42AM |
B12.00001: Nanoscale Field-Emission Devices for High-Frequency Operation Lucia De Rose, Axel Scherer, Changsoon Choi Fowler-Nordheim field emission—the emission of electrons under a strong local electric field—has been studied for over a century. However, the usage of devices based on this mechanism has been limited to niche applications like high-power RF systems and field emission displays. The preference for solid-state devices relies on its low cost, long lifetimes, low operation voltage, and simplicity of fabrication and scalability. Yet, with the advent of modern nanofabrication procedures it has been possible to fabricate nanoscale field emission devices that offer several advantages over traditional semiconductor devices. For instance, vacuum allows ballistic transport with no lattice scattering, which could allow a higher cut-off frequency than the MOSFET. |
Monday, March 14, 2022 11:42AM - 11:54AM |
B12.00002: Physics of Semiconductor Transport under High Field Conditions Mario G Ancona, Simon Cooke Semiconductor transport equations are typically derived and justified by taking moments of the microscopic Boltzmann equation. This procedure generates an infinite hierarchy of equations which must then be truncated by imposing an ad hoc closure condition in order to arrive at a useful macroscopic description. This truncation is generally done after the second (momentum) or third (energy) moment, and the resulting theories are widely used despite many questions. Among the insufficiently explored issues are: (i) when does it become necessary to include an explicit energy balance law, (ii) how important are history dependences in the description of scattering, and (iii) is electron viscosity ever a relevant concept. The present work is a progress report on our research on these foundational issues. Our effort is built on a careful examination of the underlying constitutive theory and employs a combination of hydrodynamic and Monte Carlo modeling. For the former we utilize the well-known flux-corrected transport algorithm to obtain stable time-domain solutions in 1D and 2D that include any or all of the complicating factors under study. The corresponding microscopic modeling is used for calibration purposes and is carried out with the public-domain code Archimedes. |
Monday, March 14, 2022 11:54AM - 12:06PM |
B12.00003: Anti-Stokes photoluminescence and Second-harmonic generation in two-tier nanolaminate plasmonic crystals. Rathsara R Herath Mudiyanselage, Tali S Safiabadi, Y Qian, Nicholas W Smith, Z Yuming, Ada Morral, J Song, M Nie, Brenden A Magill, Wei Zhou, Giti A Khodaparast Nanoplasmonic systems are employed to enhance nonlinear frequency conversion efficiencies at the nanoscale. Thus, these novel material systems have a wide variety of applications in developing new light sources, ultrafast sensing, optoelectronics, and also in characterization and spectroscopy. Multiresonat plasmonic structures can achieve broadband deep-subwavelength light concentration allowing efficient multiphoton nonlinear optical processes, such as second harmonic generation (SHG) and anti-Stokes photoluminescence (ASPL). In this study, we have investigated multiresonant enhancement of SHG and ASPL emissions in an Ag-SiO2-Ag nanolaminate array coated by TiO2 cladding layers of 25 nm, 60 nm, and 130 nm, respectively. These two-tier nanolaminate plasmonic crystals structures offer independent control over the plasmonic modes active at excitation and emission wavelengths. We have conducted incident power, wavelength, and polarization dependence measurements of SHG and ASPL, under ultrafast NIR illumination using a Coherent Chameleon Ti:sapphire laser with a repetition rate of 80 MHz, a wavelength range from 700 -1050 nm, and a pulse width of 140 fs. Furthermore, we provide a side-by-side analysis of the observed nonlinear emission to understand the origin of the observed SHG and ASPL in these plasmonic structures. |
Monday, March 14, 2022 12:06PM - 12:18PM |
B12.00004: An RF Photon-Number-Resolving Detector Using Majorana Zero Mode Eric Chatterjee, Wei Pan, Daniel B Soh RF photon-number-resolving detectors play an essential role in transmon quantum computers. Generally, thermal photon detectors absorb individual photons and then transfer the excess energy to lattice oscillations, yielding a temperature gain. In designing a detector, it is important to satisfy 3 criteria: establishing non-invasive bolometer capability such that absorbed photoelectrons are not washed out by the measurement process; ensuring that the temperature gain per photon is sufficiently large to be measurable; and guaranteeing that the electron-phonon heat transfer is much faster than parasitic electron losses. Here, we propose a system consisting of a p-wave superconducting nanowire side-coupled to a quantum dot (QD). The Majorana zero mode (MZM) at the edge facing the QD couples with the QD’s electronic mode. This interaction breaks the energy degeneracy, yielding composite QD-Majorana states separated by a finite energy gap, which we tune to be resonant with the incoming photon field. By analyzing the phase space, we derive the electron-phonon energy transfer rate, showing that it vastly exceeds the radiative decay rate. We also calculate the absorption rate, thus yielding the required detector density for deterministic photon number measurement. |
Monday, March 14, 2022 12:18PM - 12:30PM |
B12.00005: Charge Tunneling and Exciton Dissociation in Photochromic Molecule Bridged Quantum Dot Systems Ephraiem Sarabamoun, Lucy U Yoon, Surya B Adhikari, Jonathan M Bietsch, Esther H Tsai, Guijun Wang, Joshua J Choi The inherent limitations of electronic based computational systems has motivated many to pursue the development of alternative optical based computing. To achieve functional, high performance photonic devices an optical analog to a transistor (an optical switch) must be developed. In this work, we report a novel material system which exhibits strong, reversible, and tunable optical switching effects. Our system is composed of lead sulfide quatum dots (QDs) bridged with photochromic molecules (PCMs). By modulating the potetial barrier between the QD and PCM through optically induced chemical configuration change of the PCM, we observe dramatic changes in the photoluminescence (PL) and the excitonic lifetime. The implications of our findings in optical computing and memory devices will be discussed. |
Monday, March 14, 2022 12:30PM - 12:42PM |
B12.00006: Spin and Charge Phases in 1D Electrons Sanjeev Kumar, Michael Pepper, Patrick See, David A Ritchie, Ian Farrer, Harry Smith Transverse Electron Focusing (TEF) employs classical and quantum physics for exploring characteristics of one-dimensional (1D) systems [1]. Recently fractional conductance quantisation was reported within 1D channels [2], which appear to arise from a combination of possible spin and charge phases. In the present work, we aim to explore the characteristics of quantized 1D conductance features, particularly those which appear in the ground state due to many body interactions, using TEF. We used devices based on GaAs/AlGaAs heterostructures, where a set of gate combinations in the form of split-gate, top-gate were used to define 1D quantum wires to act as the injector and detector for TEF measurements. We observe the formation of conductance plateaus below e2/h and investigate how these can be imaged using TEF. The TEF spectrum shows a split in the odd focusing peaks, which suggests the fractional states may be spin polarised [1]. Furthermore, we will show results based on TEF including the effect of in-plane magnetic field as well as the effect of change in carrier concentration particularly in the weakly confined regime where the 1D electrons form a zigzag assembly [3]. |
Monday, March 14, 2022 12:42PM - 12:54PM |
B12.00007: Energy relaxations in hot electrons emitted by a quantum dot Dongsung T Park Mesoscopic quantum dots (QDs) are commonly used as reliable sources of hot electrons. However, we have found that two-dimensional hot electrons with excitations ≤1.5 meV may lose up to ≈ 55% of its energy immediately following their emission from a QD. The unexpected energy relaxation was identified from transverse magnetic focusing, where the focusing spectra were obtained from QD and quantum point contact (QPC) emitter experiments. Unlike its QPC counterparts, the dynamics of QD emissions significantly differed from Fermi gas predictions. With increasing hot electron energy, the focusing peaks appeared at relatively lower magnetic fields with excessive broadening. The phenomenon was modeled as an electrostatic interaction between the QD and the electron reservoir through which a hot electron may transfer its energy back to its emitter QD. Model simulations predicted a set of focusing spectra with the key features observed in experiment, implying that a QD may not be adequate as a monoenergetic source for electrons with energies beyond the QD excitation levels. |
Monday, March 14, 2022 12:54PM - 1:06PM |
B12.00008: Fast varying voltage sampling using single electron excitations within a Fabry-Perrot cavity Pascal Degiovanni, Gwendal Feve, Hubert Souquet-Basiege, Benjamin Roussel, Hugo Bartolomei, Hirosi Kamata, Ulf Gennser, Antonella Cavanna, Yong Jin, Erwann Bocquillon, Bernard Placais, Jean-Marc Berroir We present the first experimental results towards the demonstration of an "electron radar", that is a proposal for measuring time dependent electric potentials on a very short (sub-ns) time scale using an electronic interferometer fed by single electron excitations. |
Monday, March 14, 2022 1:06PM - 1:18PM |
B12.00009: Probing quantum electromagnetic magnetic fields with subnanosecond time resolution: the single electron radar Hubert Souquet-Basiège, Pascal Degiovanni, Gwendal Feve, Benjamin Roussel, Inès Safi In this talk we discuss how an electronic interferometer can be used to measure a time dependent electric field on a sub-nanosecond time scale based on alteration of the wave function of a single electronic excitation propagating across a Mach-Zenhder interferometer when the fast varying potential is appied to one of the two branches, thereby realizing the electronic analogue of a radar. |
Monday, March 14, 2022 1:18PM - 1:30PM |
B12.00010: Consistent simulation of quantum devices incorporating GaAs/AlGaAs heterostructures Eleni Chatzikyriakou, Junliang Wang, Maria Cecilia da Silva Figueira, Thomas Grange, Antonio Lacerda Santos Neto, Alex Trellakis, Christopher Bäuerle, Xavier Waintal In quantum nanoelectronics and quantum information devices, electrostatic gates control the density of the electrons and the state of the qubits1. In order to reliably predict the device characteristics, a consistent simulation method is required. In this work, a simulation model was created, that is able to self-consistently calculate the density of electrons aggregated at the interface of a GaAs/AlGaAs heterostructure by solving the Poisson and Schrödinger equations iteratively. The model was benchmarked with experimentally measured Quantum Point Contacts (QPC) of up to 27 different shapes. By solving the 3D problem, we were able to simulate the voltages at which the quantum channels become depleted as a function of the QPC shape to a very good accuracy. The variables that define the problem were captured in a minimal model, that can be used to predict the values of the parameters used in the simulation from basic wafer characteristics. |
Monday, March 14, 2022 1:30PM - 1:42PM |
B12.00011: Spin and Valley Filter Based on Two-Dimensional WSe2 Heterostructures Luis Rosales, David Zambrano, Pedro A Orellana, Andrea B Latgé In this paper we investigate the possibility of inducing and controlling spin and valley polarizations on different potential profiles of two-dimensional (2D) WSe2 heterostructures. We study the case of single and double-potential-barrier configurations. We focus on the resonant regime and how this effect allows the spin and valley polarizations. Exchange valley splitting is provided by the magnetic proximity effect, with the advantages that the splitting is dictated by the exchange interaction strength and that no applied magnetic field is required. |
Monday, March 14, 2022 1:42PM - 1:54PM |
B12.00012: In situ epitaxial aluminium gates in ultra-shallow GaAs/AlxGa1-xAs heterostructures for low noise quantum point contacts Yonatan Ashlea Alava, Daisy Q Wang, Chong Chen, David A Ritchie, Arne Ludwig, Julian Ritzmann, Andreas D Wieck, Oleh Klochan, Alex R Hamilton The mobility of the two-dimensional electron gas (2DEG) in shallow GaAs/AlxGa1−xAs heterostructures is strongly suppressed by unwanted Coulomb scattering from surface charge, likely located in native surface oxides that form after the wafer is removed from the crystal growth system. In this work, we show that this native surface oxide can be eliminated by growing an epitaxial aluminium gate before removing the wafer from the growth chamber. We examine the influence of aluminium gate thickness and the use of different semiconductor wetting layers on the semiconductor-aluminium interface and correlate this with the electron mobility. Transmission electron microscope (TEM) characterisation of the different wafers shows the in-situ epitaxial aluminium is crystalline, with a near-perfect semiconductor-aluminium interface that is oxide-free. The electron mobility is found to strongly depend on aluminium thickness, as well as the wetting layer the Al grown on. Low temperature transport measurements show the in-situ epitaxial aluminium gate design greatly reduces surface charge scattering, with up to 2.5× increase in mobility compared to a device with an ex-situ gate design. We demonstrate the use of epitaxial gates for quantum devices making a quantum point contact which shows robust and reproducible 1D conductance steps. Noise measurements reveal a reduction in charge noise of over an order of magnitude with respect to previous work, despite the 35-nm channel. |
Monday, March 14, 2022 1:54PM - 2:06PM |
B12.00013: Silver Decorated 2D Nanosheets of GO and MoS2 serve as Nanocatalyst for Water Treatment and Antimicrobial Applications as ascertained with Molecular Docking Evaluation USMAN QUMAR Synthesized Ag-MoS2 and Ag-rGO were evaluated through XRD that confirmed the hexagonal structure of MoS2 along with the transformation of GO to Ag-rGO as indicated by a shift in XRD peaks while Mo–O bonding and S=O functional groups were confirmed with FTIR. Optical properties of GO, MoS2, Ag-rGO, and Ag-MoS2 were visualized through UV–vis and PL spectroscopy. Prepared products were employed as nanocatalysts to purify industrial wastewater. Experimental results revealed that Ag-rGO and Ag-MoS2 showed 99% and 80% response in photocatalytic activity. Besides, the nanocatalyst (Ag-MoS2 and Ag-rGO) exhibited 6.05 mm inhibition zones against S. aureus gram positive (G+) and 3.05 mm for E. coli gram negative (G-) in antibacterial activity. To rationalize biocidal mechanism of Ag-doped MoS2 NPs and Ag-rGO, in silico molecular docking study was employed for two enzymes i.e. β-lactamase and D-alanine-D-alanine ligase B (ddlB) from cell wall biosynthetic pathway and enoyl-[acylcarrier-protein] reductase (FabI) from fatty acid biosynthetic pathway belonging to S. aureus. The present study provides evidence for the development of cost-effective, environment friendly and viable candidate for photocatalytic and antimicrobial applications. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700