Silicon Breakthrough Unlocks Quantum Effects at Room Temperature for Efficient Electronics

Scientists have, for the first time, optically detected the quantum Hall effect within silicon nanostructures, offering a potential pathway towards room-temperature quantum computing. N. T. Bagraev, L. E. Klyachkin, and A. N. Malyarenko, alongside N. I. Rul, demonstrate electroluminescence spectra revealing evidence of nondissipative charge transport facilitated by dipole chains within these nanostructures. This research is significant because it links observed spectral peaks to macroscopic quantum phenomena like Shubnikov, de Haas oscillations and the Hall staircase, suggesting Landau quantization induces radiation akin to Josephson and Andreev generation. Crucially, the detected spectral maxima and dips, corresponding to odd and even fractional values respectively, indicate the formation of composite bosons and fermions, potentially paving the way for more stable and efficient quantum devices.

Electroluminescence reveals quantum Hall effect in silicon nanostructures at room temperature

Scientists have demonstrated optical detection of the quantum Hall effect within silicon nanostructures, achieving a significant advance in understanding macroscopic quantum phenomena at elevated temperatures. This work reveals conditions for nondissipative transport of single charge carriers up to room temperature, a feat traditionally limited by electron-electron interactions.
The research centers on a silicon nanostructure incorporating edge channels covered by chains of dipole centers possessing negative correlation energy, enabling the observation of quantum effects without the need for ultra-low temperatures. Specifically, the study establishes a link between electroluminescence spectra and macroscopic quantum behaviours such as Shubnikov, de Haas oscillations and the quantum staircase of Hall resistance.

The observed consistency between spectral peaks in electroluminescence and these quantum phenomena supports a model based on Faraday electromagnetic induction, suggesting Landau quantization induces irradiation akin to Josephson and Andreev generation. Detected maxima in spectral characteristics align with odd fractional values of the resistance quantum staircases, while dips correspond to even fractional values, indicating increased formation of composite bosons and fermions.

This differentiation is attributed to the unique properties of the negative-U dipole center chains, which suppress electron-electron interactions and facilitate energy exchange. Researchers fabricated the silicon nanostructure using planar technology on a monocrystalline silicon (100) surface, employing boron diffusion to create the negative-U dipole centers.

This process resulted in an ultra-narrow quantum well, 2nm in width, confined by quasi-one-dimensional boron chains. Despite a high boron concentration of 5 × 1021cm-3, the edge channels exhibited no activity in electron paramagnetic resonance (EPR) measurements, yet displayed a significant diamagnetic response via Faraday method analysis.

This innovative approach not only allows for the study of macroscopic quantum phenomena at higher temperatures but also provides a means to investigate quantum interference of single charge carriers within the edge channel pixels. The observed effects suggest these pixels function as quantum boxes, offering opportunities to evaluate the contributions of both equilibrium and non-equilibrium effects to quantum interference processes. The findings open avenues for exploring advanced quantum devices and materials with tailored electronic properties.

Fabrication and characterisation of boron-diffused silicon quantum wells

Silicon nanostructures were fabricated using planar technology on a monocrystalline silicon (100) surface to demonstrate electroluminescence spectra with edge channels covered by chains of dipole centers with negative correlation energy. The fabrication process began with preliminary oxidation followed by photolithography and gas-phase boron diffusion to create the desired nanostructure.

Thermal oxidation conditions were carefully optimised to achieve an ultra-shallow diffusion profile, balancing vacancy and kick-out diffusion mechanisms, ultimately passivating the boundaries of an ultra-narrow quantum well with boron centers. This resulted in an ultra-narrow quantum well, 2nm in width, confined by quasi-one-dimensional barriers composed of boron chains spaced 2nm apart.

Secondary Ion Mass Spectrometry (SIMS) data indicated a high boron concentration of 5 × 1021cm-3, yet Electron Paramagnetic Resonance (EPR) measurements showed no activity in the edge channels of the quantum well. Instead, field-dependent magnetization studies employing the Faraday method revealed a significant diamagnetic response in weak magnetic fields, suggesting passivation of the edge channel by boron impurity centers responsible for single-carrier transport.

The ground state of these impurity shells consists of chains of negative-U dipole boron centers, as evidenced by the observed diamagnetic response when the nanostructure is subjected to an external magnetic field. Electrical and optical measurements were then performed to characterise the quantum Hall effect.

Longitudinal (Rxx) and lateral (Rxy) resistances were measured at 77 K with a stabilised drain-source current of 10 nA, revealing Shubnikov, de Haas oscillations, a quantum staircase of Hall resistance, a quantum staircase of conductance, and multiple Andreev reflections. The observed characteristics are directly linked to Landau quantization processes within each pixel of the edge channel, with the step height in the Hall dependence determined by the induced generation current and pixel geometry.

Electroluminescence correlates fractional quantum Hall states with silicon nanostructure irradiation

Electroluminescence spectra revealed the presence of a silicon nanostructure featuring edge channels covered by chains of dipole centers with negative correlation energy. These chains facilitate nondissipative transport of single charge carriers at elevated temperatures, extending up to room temperature.

Suppression of electron-electron interactions allows macroscopic quantum phenomena, specifically Shubnikov, de Haas oscillations and the quantum staircase of Hall resistance, to align with the spectral peaks detected via electroluminescence. The observed results are interpreted within the framework of Faraday electromagnetic induction, suggesting that Landau quantization induces irradiation analogous to Josephson and Andreev generation.

Detected maxima in the spectral characteristics consistently correspond to odd fractional values of the resistance quantum staircases. Conversely, dips in the electroluminescence spectra appear at even fractional values of the resistance quantum ladder, attributable to increased formation of composite bosons and fermions.

This behavior demonstrates a correlation between the observed optical signals and the quantum Hall effect within the silicon nanostructure. The work utilizes boron centers embedded within monocrystalline silicon wafers, fabricated in a Hall geometry, as the negative-U dipole centers. The formation of impurity dipoles, resulting from the dissociation of neutral negative-U centers, contributes to the suppression of electron-electron interactions.

Edge channel shells consisting of chains of these negative-U dipole centers segment the channels into sections containing single charge carriers, ensuring conditions for nondissipative transport through energy exchange. Nearly nondissipative transport of single charge carriers is achieved within these pixelated edge channels, facilitated by hole tunneling and ultrafast formation of negative-U dipole centers. The initial reduction in entropy within the nanostructure, due to the negative-U shells, enables the observation of macroscopic quantum phenomena at high temperatures and allows for the study of quantum interference of single charge carriers.

Spectral signatures correlate fractional quantum Hall effect with terahertz emission

Electroluminescence spectra from a silicon nanostructure incorporating edge channels and dipole center chains reveal conditions for nondissipative charge carrier transport at temperatures up to room temperature. The suppression of electron-electron interactions within this structure correlates with macroscopic quantum phenomena, specifically Shubnikov, de Haas oscillations and the Hall staircase, aligning with the observed spectral peaks.

These findings suggest a connection between Landau quantization and induced radiation, analogous to Josephson and Andreev generation mechanisms. Detected maxima in the spectral characteristics correspond to odd fractional quantum Hall effect (QHE) values, while dips occur at even fractional values, indicating enhanced formation of composite bosons and fermions respectively.

This consistency between electrical resistance measurements and terahertz electroluminescence spectra demonstrates a strong link between Landau quantization and the observed optical signals. The research establishes the first experimental detection and identification of both integral and fractional QHEs within the silicon nanostructure through analysis of electroluminescence spectra obtained via infrared Fourier spectroscopy.

This work demonstrates the feasibility of optically detecting the quantum Hall effect by utilising the principles of Faraday electromagnetic induction. The strong agreement between lateral and longitudinal resistance characteristics and terahertz electroluminescence spectra confirms the role of Landau quantization in the observed phenomena. Limitations acknowledged by the authors are not explicitly stated within the manuscript itself.