Quantum Sensing Microscopy

To date, insights on the electronic properties of quantum materials often hinge on non-local transport experiments, which measure a global resistance drop across a device, and on other experimental techniques, such as photoelectron spectroscopy and STM, that can map out the equilibrium electronic density of states. All these measurements are however inherently insensitive to charge carrier dynamics at small length scales, which dictate the global properties of quantum materials and which will be of relevance for the integration of these material platforms into future electronic devices. The future exploration of quantum materials will, therefore, be accelerated by the concurrent development of new measurement techniques with the ability to measure such local transport properties with high sensitivity and high spatial resolution.

Inspired by the recent advances in imaging transport-related properties of conducting samples (1-3), we seek to implement scanning charge qubit microscopy (SCQM) as a novel quantum sensing microscopy to visualize dissipative charge carrier dynamics with estimated nanometer spatial and high temporal resolution (4). SCQM is based on the high sensitivity of superconducting charge qubits to charge noise and employs the qubit’s decoherence time as a quantitative probe for the resistivity and temperature of a sample. A nanowire tip attached to the qubit realizes a local geometric coupling capacitance that converts voltage noise in the sample to charge noise on the qubit, inducing decoherence that can be measured in a circuitQED scheme.

SCQM will be especially well-suited to study the microscopic mechanism of interaction driven quantum phase transitions in low-dimensional correlated phases of matter and to visualize edge modes of novel topological materials. It should also enable the investigation of charge carrier dynamics in mesoscopic and nanoscale devices directly relevant to technological applications, where energy dissipation deteriorates the performance of superconducting qubits. Read more.

(1) Y.-T. Cui et al., Rev. Sci. Instrum. 87, 063711 (2016).
(2) A. Ariyaratne et al., Nature Comms. 9, 2406 (2018).
(3) D. Halbertal et al., Nature 539, 407-410 (2016).
(4) B. Jäck, arXiv:1910.03583 [cond-mat.mes-hall] (2019).