94 research outputs found
Atomic-scale authentication with resonant tunneling diodes
The room temperature electronic characteristics of resonant tunneling diodes (RTDs) containing AlAs/InGaAs quantum wells are studied. Differences in the peak current and voltages, associated with device-to-device variations in the structure and width of the quantum well are analyzed. A method to use these differences between devices is introduced and shown to uniquely identify each of the individual devices under test. This investigation shows that quantum confinement in RTDs allows them to operate as physical unclonable functions
Atomic-scale authentication using resonant tunnelling diodes
The rapid development of technology has provided a wealth of resources enabling the trust of everyday interactions to be undermined. Authentication schemes aim to address this challenge by providing proof of identity. This can be achieved by using devices that, when challenged, give unique but reproducible responses. At present, these distinct signatures are commonly generated by physically unclonable functions, or PUFs. These devices provide a straightforward measurement of a physical characteristic of their structure that has inherent randomness, due to imperfections in the manufacturing process. These hard-to-predict physical responses can generate a unique identity that can be used for authentication without relying on the secrecy of stored data. However, the classical design of these devices limits both their size and security. Here we show that the extensively studied problematic fluctuations in the current-voltage measurements of resonant tunnelling diodes (RTDs) provide an uncomplicated, robust measurement that can function as a PUF without conventional resource limitations. This is possible due to quantum tunnelling within the RTD, and on account of these room temperature quantum effects, we term such devices QUFs - quantum unclonable functions. As a result of the current-voltage spectra being dependent on the atomic structure and composition of the nanostructure within the RTD, each device provides a high degree of uniqueness, whilst being impossible to clone or simulate, even with state-of-the-art technology. We have thus created PUF-like devices requiring the fewest resources which make use of quantum phenomena in a highly manufacturable electronic device operating at room temperature. Conventional spectral analysis techniques, when applied to our QUFs, will enable reliable generation of unpredictable unique identities which can be employed in advanced authentication systems
Continuous pulse advances in the negative ion source NIO1
Consorzio RFX and INFN-LNL have designed, built and operated the compact
radiofrequency negative ion source NIO1 (Negative Ion Optimization phase 1)
with the aim of studying the production and acceleration of H- ions. In
particular, NIO1 was designed to keep plasma generation and beam extraction
continuously active for several hours. Since 2020 the production of negative
ions at the plasma grid (the first grid of the acceleration system) has been
enhanced by a Cs layer, deposited though active Cs evaporation in the source
volume. For the negative ion sources applied to fusion neutral beam injectors,
it is essential to keep the beam current and the fraction of co-extracted
electrons stable for at least 1 h, against the consequences of Cs sputtering
and redistribution operated by the plasma. The paper presents the latest
results of the NIO1 source, in terms of caesiation process and beam
performances during continuous (6{\div}7 h) plasma pulses. Due to the small
dimensions of the NIO1 source (20 x (diam.)10 cm), the Cs density in the volume
is high (10^15 \div 10^16 m^-3) and dominated by plasma-wall interaction. The
maximum beam current density and minimum fraction of co-extracted electrons
were respectively about 30 A/m^2 and 2. Similarly to what done in other
negative ion sources, the plasma grid temperature in NIO1 was raised for the
first time, up to 80 {\deg}C, although this led to a minimal improvement of the
beam current and to an increase of the co-extracted electron current.Comment: 11 pages, 7 figures. Contributed paper for the 8th International
symposium on Negative Ions, Beams and Sources - NIBS'22. Revision 1 of the
preprint under evaluation at Journal of Instrumentation (JINST
Electron-paramagnetic-resonance identification of silver centers in silicon
©19xx American Physical Societ
Direct Determination of 3D Distribution of Elemental Composition in Single Semiconductor Nanoislands by Scanning Auger Microscopy
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