Combining multiplexed gate-based readout and isolated CMOS quantum dot arrays.

Area of Science:

• Quantum Computing
• Condensed Matter Physics
• Nanotechnology

Background:

• Semiconductor quantum dot arrays are a leading platform for spin-based quantum computation.
• Scaling quantum dot arrays for large qubit numbers is hindered by complex charge configurations and limited sensor sensitivity.

Purpose of the Study:

• To demonstrate a scalable method for achieving single-spin occupancy in each quantum dot within an array.
• To overcome challenges in charge readout and control for large-scale quantum computing architectures.

Main Methods:

• Loading a finite number of electrons into foundry-fabricated quantum dot arrays to simplify electrostatic tuning by isolating them from reservoirs.
• Employing multiplex gate-based reflectometry for dispersive probing of charge tunneling and spin states, eliminating the need for external charge sensors.

Main Results:

• Successful demonstration of single-spin occupancy in each dot of the quantum dot array.
• Achieved simplified electrostatic tuning of isolated quantum dot arrays.
• Validated multiplex reflectometry as an effective readout method for charge and spin states.

Conclusions:

• The combination of isolated electron loading and multiplex reflectometry offers a viable and scalable approach for spin-based quantum architectures.
• This method facilitates the electrostatic tuning of quantum dot arrays, paving the way for larger qubit systems.
• The demonstrated technique addresses key challenges in scaling up quantum dot-based quantum computers.