Highly Sensitive Nanoscale Scanning Magnetic and Thermal Sensor

The Need

In light of the rapidly developing scanning-probe based technologies including nanomagnetism, spintronics, energyefficient computing and quantum computing, there is a pertinent need for the development of nanoscale sensor devices for direct magnetic field and thermal imaging with high sensitivity and spatial resolution. The effective spatial resolution is determined by the size of the sensor and its proximity to the sample. The existing superconducting quantum interference (SQUID) sensors based on planar technology are limited in their size and in ability to closely approach the surface of a sample.

In addition, owing to the detrimental effect of dissipation on quantum information, study of the underlying mechanisms is of particular importance. In order to preserve a quantum state, for instance, in the case of a qubit, the dissipation has to be extremely weak, i.e., at magnitudes several orders below the best sensitivity (several mK/Hz1/2) of any of the existing thermal imaging techniques. Moreover, none of these imaging techniques has been demonstrated to operate at the low temperatures that are essential for study of quantum systems.

The Solution

Nanoscale SQUID-on-tip device that enables high spatial, magnetic and thermal resolution for local measurements by minimizing the sensor size and the distance between the sensor and the sample.

Technology Essence

The present invention is a novel sensor device, based on nanoscale two-junction or multi-junction SQUIDs fabricated on the edge of a sharp tip in a three-dimensional geometric configuration. In such a setup, the SQUID can approach the sample to a distance of several nanometers. The small size of the sensor device and its ability to be placed at a short distance from the sample surface, result in extremely high sensitivity. The novel threedimensional geometrical configuration of the SQUID-on tip is obtained by focused ion beam milling, which enables measurement of both in-plane and out-of-plane components of the magnetic field with a remarkable sensitivity. The capability to measure in-plane fields enables use of this novel sensor device for applications such as in-plane spin detection and transport current distribution in complex systems. The unique nanoscale cross-section geometry of the device allows for non-contact, nanoscale-resolution sensing of the local temperature of a sample. This tool enables scanning cryogenic thermal sensing that is 4 orders of magnitude more sensitive than other devices, allowing for the detection of high thermal resolution .

Applications

• Scanning probe microscopy for magnetic and thermal characterization
• Inspection and probing equipment for quantum computing

Development Status

SQUID-on-tip devices were fabricated and tested, under laboratory conditions, to measure local magnetic signals and thermal dissipation processes in model systems (Published in: Nat. Nanotechnol. 2013, 8: 639:644 [1]).

Market Opportunity

Various industries use scanning probe microscopes to improve quality control and assurance and enhance overall product development. Key end-use industries include semiconductor, personal care and food science industries. According to a recent market report, the scanning probe microscope market is expected to grow at a CAGR of 7.1% during 2017-2026. Nanomechanical characterization with the help of scanning probe microscopy is quickly gaining traction, further promoting growth of the market.

The constant research advancements in the quantum computing field is projected to rapidly grow the market at a CAGR of 29% during 2017-2023. The quantum computing processor, a physical device enabling the principle of quantum computing, is still a rather theoretical concept than a ready-to-implement engineering solution. At the same time, this rapidly evolving market is one of the most active R&D fields, attracting substantial government funding that supports research groups at internationally leading academic institutions, national laboratories, and major industrial-research centers. The governments are the major driving force behind investments in quantum computing R&D, fiercely competing for what is perceived as one of the most promising technologies of the 21st century.