On-chip thermometry at millikelvin temperatures for quantum-classical electronics co-integration

/ On-chip thermometry at millikelvin temperatures for quantum-classical electronics co-integration

On-chip thermometry at millikelvin temperatures for quantum-classical electronics co-integration

Master internship - Leuven | More than two weeks ago

Probe temperature on cryogenic CMOS electronics close to absolute zero to enable scalable quantum computing applications

Quantumcomputing has the potential to revolutionize information processing byperforming computations beyond the reach of classical computers. This willrequire the operation of quantum processors containing millions of extremelysensitive qubits, located inside dilution refrigerators and operated at temperaturesnear 10 millikelvin. Current experimental systems, however, are limited to onlya few hundred qubits. This is due in part to the input-output bottleneck, whichgreatly limits qubit control at scale.

Cryogenic CMOScircuits, closely integrated with quantum circuits, have been proposed as asolution to alleviate this input-output bottleneck and allow for the operationof large-scale quantum processors [1]. Achieving this is especiallychallenging, due to the extremely stringent thermal and noise requirements ofquantum bits and of the cryogenic environment. Accurate temperature sensing istherefore critical for the characterization, validation and optimization of suchchips at deep cryogenic temperatures. However, conventional temperature sensorsoften lack the required sensitivity or resolution and cannot be directlyintegrated on CMOS chips for characterization.

In this Masterthesis, you will investigate CMOS-compatible on-chip thermometry techniquessuitable for millikelvin temperatures, with a focus on semiconductor devicessuch as diodes or bipolar junction transistors (BJTs) [2]. This work will consistof cryogenic electrical measurements in a dilution refrigerator, performed attemperatures down to 10 mK. It could include the development of calibration andmeasurement protocols for the accurate extraction of the local temperature atdifferent areas of a chip. The thesis aims to quantify the impact of cryogeniccircuits operating in different modes on the local temperature, both within andoutside the chip, and to assess the relevance of thermal effects for closerintegration with quantum processors.

Requiredbackground: Electrical engineering, Physics

Type of work: 20%literature, 40% measurements and experiments, 40% data analysis

Promotor: BartSoree

Required educational background: Nanoscience & Nanotechnology, Electrotechnics/Electrical Engineering, Physics

University promotor: Bart Soree (KU Leuven)

The reference code for this position is 2026-INT-103. Mention this reference code in your application.

Only for self-supporting students.

Quantumcomputing has the potential to revolutionize information processing byperforming computations beyond the reach of classical computers. This willrequire the operation of quantum processors containing millions of extremelysensitive qubits, located inside dilution refrigerators and operated at temperaturesnear 10 millikelvin. Current experimental systems, however, are limited to onlya few hundred qubits. This is due in part to the input-output bottleneck, whichgreatly limits qubit control at scale.

Cryogenic CMOScircuits, closely integrated with quantum circuits, have been proposed as asolution to alleviate this input-output bottleneck and allow for the operationof large-scale quantum processors [1]. Achieving this is especiallychallenging, due to the extremely stringent thermal and noise requirements ofquantum bits and of the cryogenic environment. Accurate temperature sensing istherefore critical for the characterization, validation and optimization of suchchips at deep cryogenic temperatures. However, conventional temperature sensorsoften lack the required sensitivity or resolution and cannot be directlyintegrated on CMOS chips for characterization.

In this Masterthesis, you will investigate CMOS-compatible on-chip thermometry techniquessuitable for millikelvin temperatures, with a focus on semiconductor devicessuch as diodes or bipolar junction transistors (BJTs) [2]. This work will consistof cryogenic electrical measurements in a dilution refrigerator, performed attemperatures down to 10 mK. It could include the development of calibration andmeasurement protocols for the accurate extraction of the local temperature atdifferent areas of a chip. The thesis aims to quantify the impact of cryogeniccircuits operating in different modes on the local temperature, both within andoutside the chip, and to assess the relevance of thermal effects for closerintegration with quantum processors.

Requiredbackground: Electrical engineering, Physics

Type of work: 20%literature, 40% measurements and experiments, 40% data analysis

Promotor: BartSoree

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