Quantum Materials and Devices (QMD)

Our group is interested in the development of quantum materials and devices towards a scalable quantum computer. The key challenges are to obtain long coherence time, low error rate and a scalable platform to increase the number of qubits. We exploit the unique electrical and optical properties in ultra-thin 2-dimensional transition metal chalcogenides (TMDCs) materials such as spin-valley interlocking, spin-orbit coupling and possibility of integration with CMOS process to tackle these challenges.

What we do: Our research is focused on the development of high-quality materials in a scalable device architecture which constitute the current major bottleneck towards a scalable quantum computer. We have developed a strong suite of capabilities in quantum material and solid-state device development which enables us to tackle these challenges.

Approach: Our strategy is to develop all scalable processes for device fabrication such as chemical vapor deposition grown TMDC, atomic layer deposition high-k dielectric layer and lithographically defined metallic gates to create spin-valley qubits.

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Materials Growth and Quality

QMD hosts a range of materials growth and characterization expertise:

  • CVD – planarTECH plasma enhanced chemical vapour deposition system for the synthesis of high quality WS2
  • ARPES – PREVAC angle-resolved photoelectron spectroscopy with spin polarized detector for band structure characterization
  • CDPL – Home-built circular dichroic photoluminescence system for the measurement of valley polarization
  • STM – Omicron low temperature scanning tunneling microscopy and Nanoprobe system for atomic defects characterization and device measurements

Additional support tools from IMRE’s shared facilities include atomic layer deposition, electron beam lithography and various material evaporators.

Electrical Measurements

Quantum devices are characterized at cryogenic temperatures. For this, QMD hosts 2 dilution refrigerators (DRs) reaching a base temperature of 10mK and equipped with 3-axis vector magnet (9-1-1T and 6-1-1T), 48 DC lines and low noise measurement capability. For qubit control and manipulation, DR hosts 8 radio frequency lines with bandwidth of 10 GHz.

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Achievements and Highlights

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Group Leader Contact Details:

Dr. Kuan Eng Johnson Goh
Email: gohj@imre.a-star.edu.sg