Universal signal scaling in microwave impedance microscopy

Journal Article · Wed Sep 21 00:00:00 EDT 2022 · Applied Physics Letters

DOI:https://doi.org/10.1063/5.0115833· OSTI ID:1888295

Shan, Jun-Yi  ^[1]; Pierce, Adam  ^[2]; Ma, Eric Y.  ^[1]

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1. University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
2. University of California, Berkeley, CA (United States)

Microwave impedance microscopy (MIM) is an emerging scanning probe technique that measures the local complex dielectric function using near-field microwave. Although it has made significant impacts in diverse fields, a systematic, quantitative understanding of the signal's dependence on various important design parameters is lacking. Here, we show that for a wide range of MIM implementations, given a complex tip-sample admittance change ΔΥ, the MIM signal—the amplified change in the reflected microwave amplitude—is –G · ΔΥ/2Υ₀ · η² · V_in, where η is the ratio of the microwave voltage at the probe to the incident microwave amplitude, Y_o is the system admittance, and G is the total voltage gain. For linear circuits, η is determined by the circuit design and does not depend on V_in. We show that the maximum achievable signal for different designs scales with η² or η when limited by input power or sample perturbation, respectively. Furthermore, this universal scaling provides guidance on diverse design goals, including maximizing narrow-band signal for imaging and balancing bandwidth and signal strength for spectroscopy.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1888295
• Alternate ID(s): OSTI ID: 1888597; OSTI ID: 1960235
• Journal Information: Applied Physics Letters, Vol. 121, Issue 12; ISSN 0003-6951
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
Reflectometry
Signal-to-noise ratio
Radiowave and microwave technology
Signal processing
Dimensional analysis
Linear circuit
Microwave impedance microscopy
Tuning forks
Electronic circuits
Spectroscopy
reflectometry
signal-to-noise ratio
radiowave and microwave technology
signal processing
dimensional analysis
linear circuit
microwave impedance microscopy
tuning forks
electronic circuits
spectroscopy