Caner Toprak - DR Project
Doctoral Researcher: Caner Toprak
Local Supervisor: Lammert Duipmans
Academic Supervisor: Lotte Geck, RWTH Aachen / ICA
Topic: Quantum Computing
Research Field: Information
Control Electronics for Scalable Qubit Architectures
Today’s largest quantum processors utilize commercially-available arbitrary waveform generators to provide the necessary signals to control the qubits. These signals are carried from room temperature to the qubits inside a dilution refrigerator at sub-Kelvin temperatures over coaxial cables. Furthermore, each qubit requires many signals with various properties (frequency, amplitude, shape, etc.) for their proper operation. These facts constitute fundamental limitations in terms of scalability for the existing architectures.
The proposed solutions are two-fold: on the one side, there are modular qubit architectures, and on the other side integration of control electronics with the qubits. Fulfillment of the second part requires overcoming numerous challenges. Among these are the tight power budget, noise budget, and high wiring density.
The power budget can partially be relaxed by a better-optimized placement of the parts of the circuit at different temperature stages of the refrigerator. Additionally, the noise budget can be maintained by careful consideration of the trade-off between it and the power consumption. While the wiring density is mainly determined by the qubit architecture, there are tools on the electronics side, such as time-division multiple access. However, this too has its drawbacks as increased complexity, and in turn higher power consumption. Moreover, the qubits have a short time frame in which they remain coherent for the quantum-logic operations to be completed.
The points made above demonstrate the complexity and entwined nature of different problems and their solutions regarding scalability of quantum processors. Consequently, a holistic, system-level approach is suggested in this project that considers all the aspects above.
Caner Toprak
Doctoral Researcher
- Peter Grünberg Institute (PGI)
- Integrated Computing Architectures (PGI-4)
Room 200F