Periodic Reporting for period 3 - UltraFastNano (Electronic generation and detection in nanoelectronic devices at the picosecond scale)
Periodo di rendicontazione: 2023-01-01 al 2024-12-31
Quantum Technology is a radically new form of information technology with the potential to become a major industry, comparable to conventional IT, and crucial for the digital single market and economic growth. Massive global investments are driving its development.
Most quantum technologies focus on localized quantum states, like superconducting circuits or trapped electron spins. In contrast, this project explores propagating quantum states at frequencies beyond 10 GHz. At these scales, excitations behave like electrons or photons, enabling applications in quantum communication, sensing, and computation. Pushing further into the THz regime is extremely challenging for electronics—until now, only optical methods could access such timescales electrically.
UltraFastNano aims to create the first quantum nanoelectronics platform operating at picosecond timescales. For example, semiconductor qubits have naturally short coherence times, requiring ultrafast operation. A key performance measure is the ratio between a qubit’s coherence time and its operation time. With UltraFastNano, we will push operation speeds to 1 picosecond, unlocking new potential for quantum nanoelectronics.
The UltraFastNano project will pioneer new concepts at the crossroads between quantum optics and solid-state nanoelectronics. Its aim is to achieve full control of quantum excitations that propagate through the quantum devices on the picosecond scale, about three orders of magnitude faster than other quantum technologies. The main objectives include
• Picosecond on-demand coherent single-particle source
• Single-shot detection of propagating excitations at the discrete charge level
• Quantum interferometry at the single-charge level
• New software for predictive simulation and optimisation of ultrafast quantum devices.
In the UltraFastNano project, we have developed the foundation for a quantum technology based on propagating electron wave packets. This approach holds the potential to significantly reduce the hardware footprint compared to mainstream quantum computing methods. A patent has been filed to protect this new quantum architecture.
In the future, connecting this architecture with photonic systems will be important for enabling long-distance quantum communication. As an initial step, we have developed an electron-photon interface, for which a separate patent has been filed.
Most quantum technologies focus on localized quantum states, like superconducting circuits or trapped electron spins. In contrast, this project explores propagating quantum states at frequencies beyond 10 GHz. At these scales, excitations behave like electrons or photons, enabling applications in quantum communication, sensing, and computation. Pushing further into the THz regime is extremely challenging for electronics—until now, only optical methods could access such timescales electrically.
UltraFastNano aims to create the first quantum nanoelectronics platform operating at picosecond timescales. For example, semiconductor qubits have naturally short coherence times, requiring ultrafast operation. A key performance measure is the ratio between a qubit’s coherence time and its operation time. With UltraFastNano, we will push operation speeds to 1 picosecond, unlocking new potential for quantum nanoelectronics.
The UltraFastNano project will pioneer new concepts at the crossroads between quantum optics and solid-state nanoelectronics. Its aim is to achieve full control of quantum excitations that propagate through the quantum devices on the picosecond scale, about three orders of magnitude faster than other quantum technologies. The main objectives include
• Picosecond on-demand coherent single-particle source
• Single-shot detection of propagating excitations at the discrete charge level
• Quantum interferometry at the single-charge level
• New software for predictive simulation and optimisation of ultrafast quantum devices.
In the UltraFastNano project, we have developed the foundation for a quantum technology based on propagating electron wave packets. This approach holds the potential to significantly reduce the hardware footprint compared to mainstream quantum computing methods. A patent has been filed to protect this new quantum architecture.
In the future, connecting this architecture with photonic systems will be important for enabling long-distance quantum communication. As an initial step, we have developed an electron-photon interface, for which a separate patent has been filed.
RP2 & RP1 were described in the previous report:
RP3:
During the fourth and fifth years of the UltraFastNano project, we successfully addressed and completed nearly all of the project's objectives. The achievements realised throughout the entire project are summarised below:
Overall Achievements of the UltraFastNano Project
• Development of a Novel Voltage Generator
A cutting-edge voltage generator based on a frequency comb has been created, enabling the generation and detection of electron wave packets with a temporal duration of just 27 ps—the shortest reported to date.
• Realization of a Single-Electron Detector
A detector for propagating electron wave packets was successfully developed, achieving a sensitivity of four electrons. With optimized design architecture and the use of tailored quantum materials, improvements to single-electron sensitivity are within reach.
• Generation of Single Acoustic Pulses
Techniques developed in the project were successfully applied to generate single acoustic pulses, paving the way for novel applications in quantum acoustics.
• Electron Antibunching Demonstration
Using the developed techniques, the antibunching of two individual electrons was demonstrated, highlighting advancements in single-electron quantum control.
• Dynamic Two-Particle Interferometry
A novel interferometry method was developed to quantify the quantum coherence of a fractional quantum Hall channel, contributing to the understanding of quantum correlations in exotic states of matter.
• Electronic Interferometry of Ultrashort Electron Wave Packets
Ultrashort electron wave packets were successfully used in a 14-micrometer-long Mach-Zehnder interferometer, demonstrating coherent quantum transport over unprecedented distances.
• New Tools for Electrostatic Modelling
Advanced tools were developed for realistic electrostatic modeling of GaAs-based nanoelectronic devices, improving the design and understanding of nanoscale systems.
• Impact of channel mixing identified.
Channel mixing has been identified as an until now disregarded effect that can impact interferometry with single-particle pulses. First experimental results support the developed theory.
• Development of Tkwant Software
The project developed Tkwant, a new software tool that enables the simulation of time-dependent quantum transport in nanoelectronic devices, bridging theoretical and experimental research.
RP3:
During the fourth and fifth years of the UltraFastNano project, we successfully addressed and completed nearly all of the project's objectives. The achievements realised throughout the entire project are summarised below:
Overall Achievements of the UltraFastNano Project
• Development of a Novel Voltage Generator
A cutting-edge voltage generator based on a frequency comb has been created, enabling the generation and detection of electron wave packets with a temporal duration of just 27 ps—the shortest reported to date.
• Realization of a Single-Electron Detector
A detector for propagating electron wave packets was successfully developed, achieving a sensitivity of four electrons. With optimized design architecture and the use of tailored quantum materials, improvements to single-electron sensitivity are within reach.
• Generation of Single Acoustic Pulses
Techniques developed in the project were successfully applied to generate single acoustic pulses, paving the way for novel applications in quantum acoustics.
• Electron Antibunching Demonstration
Using the developed techniques, the antibunching of two individual electrons was demonstrated, highlighting advancements in single-electron quantum control.
• Dynamic Two-Particle Interferometry
A novel interferometry method was developed to quantify the quantum coherence of a fractional quantum Hall channel, contributing to the understanding of quantum correlations in exotic states of matter.
• Electronic Interferometry of Ultrashort Electron Wave Packets
Ultrashort electron wave packets were successfully used in a 14-micrometer-long Mach-Zehnder interferometer, demonstrating coherent quantum transport over unprecedented distances.
• New Tools for Electrostatic Modelling
Advanced tools were developed for realistic electrostatic modeling of GaAs-based nanoelectronic devices, improving the design and understanding of nanoscale systems.
• Impact of channel mixing identified.
Channel mixing has been identified as an until now disregarded effect that can impact interferometry with single-particle pulses. First experimental results support the developed theory.
• Development of Tkwant Software
The project developed Tkwant, a new software tool that enables the simulation of time-dependent quantum transport in nanoelectronic devices, bridging theoretical and experimental research.
The long-term vision of UltraFastNano includes the much-needed quantum bus allowing direct interaction between distant quantum bits, hence a drastic reduction of the hardware footprint for quantum error correction protocols. It also includes the possibility of more disruptive quantum technologies such as flying qubit architectures, a radically different route from the mainstream semiconducting or super-conducting approach followed by the major nanoelectronic companies (Google, IBM, Intel, etc.).
UltraFastNano aims to achieve these goals be fighting decoherence with a dramatic increase of operation speed. In the long-term, pushing towards this frequency range will enable quantum technologies that operate without the need of a cryogenic environment (6 THz 300K).
The three technological milestones of UltraFastNano –
(i) 1 ps single-electron source,
(ii) single-electron detection and
(iii) optoelectronic interface
– have important potential for triggering disruptive innovation on ultrafast electronics for (cryogenic) THz voltage source or detection. This novel and efficient method for generating ultrafast pulses can find numerous applications for on-chip THz spectroscopy and for THz wireless communications. UltraFastNano will also find immediate applications for metrologically-accurate measurements of the ampere and picosecond optoelectronic devices that convert between electronic and photonic excitations.
In addition, the simulation tools developed within the UltraFastNano project will be directly integrated into nextnano commercial products/software. The implemented features will increase the capabilities of the nextnano software in simulating a large range of nanoelectronic devices such as silicon nanowire transistors or silicon spin qubits.
Throughout the UltraFastNano (UFN) project, strained Germanium emerged as a highly promising quantum material for advanced quantum technologies. This material exhibits exceptional properties, including notably long coherence times for spin qubits as well as ballistic propagation for single charge wavepackets. This breakthrough has opened the door to adapting flying qubit technology to the Germanium platform. Building on this foundation, further exploration will be undertaken in the newly launched EIC-PATHFINDER project, "ELEQUANT."
UltraFastNano aims to achieve these goals be fighting decoherence with a dramatic increase of operation speed. In the long-term, pushing towards this frequency range will enable quantum technologies that operate without the need of a cryogenic environment (6 THz 300K).
The three technological milestones of UltraFastNano –
(i) 1 ps single-electron source,
(ii) single-electron detection and
(iii) optoelectronic interface
– have important potential for triggering disruptive innovation on ultrafast electronics for (cryogenic) THz voltage source or detection. This novel and efficient method for generating ultrafast pulses can find numerous applications for on-chip THz spectroscopy and for THz wireless communications. UltraFastNano will also find immediate applications for metrologically-accurate measurements of the ampere and picosecond optoelectronic devices that convert between electronic and photonic excitations.
In addition, the simulation tools developed within the UltraFastNano project will be directly integrated into nextnano commercial products/software. The implemented features will increase the capabilities of the nextnano software in simulating a large range of nanoelectronic devices such as silicon nanowire transistors or silicon spin qubits.
Throughout the UltraFastNano (UFN) project, strained Germanium emerged as a highly promising quantum material for advanced quantum technologies. This material exhibits exceptional properties, including notably long coherence times for spin qubits as well as ballistic propagation for single charge wavepackets. This breakthrough has opened the door to adapting flying qubit technology to the Germanium platform. Building on this foundation, further exploration will be undertaken in the newly launched EIC-PATHFINDER project, "ELEQUANT."