Sensing real world systems with quantum defects in diamond at room temperature

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Abstract: Diamond quantum defects exhibit remarkable properties at the confluence of biological and quantum sciences. The crystalline carbon lattice of this material acts as both a quantum vacuum, allowing long lived coherent states at room temperature, and a bio-friendly interface. Because of these properties, defect centres (qubits) in diamond are driving advances in quantum computing and sensing applications.1-2 I will detail our group’s application of these nano-scale sensors to a variety of bio-imaging and novel solid-state sensing experiments. However, as these technologies begin to be applied in real devices, these optically active defects are also being increasingly located within nanometres of the diamond surface,3 where their quantum properties such as coherence time and spectral width are reported to experience significant degradation,4 compared to their bulk properties. I will also detail our efforts to deal with these challenges, through novel measurements and modification of the diamond surface chemistry. I will provide experimental evidence of unexpected crystalline defects at the diamond surface, as well as theoretical calculations showing that these defects produce low-lying trap states in the near-surface region, inhibiting the charge population and stability of near-surface NV centres; and provide pathways for the removal of these defects.

 

Speaker Bio: 

Dr Alastair Stacey is a Research Fellow in Quantum Sensing with the Centre of Excellence in Quantum Computing and Communication Technology and an ANFF-Vic Technology Ambassador in diamond technologies at the Melbourne Centre for Nanofabrication. He is a diamond synthesis and technologies expert with industry experience and a focus on translational research. 

Ref:

1. Rondin, L.; Tetienne, J. P.; Hingant, T.; Roch, J. F.; Maletinsky, P.; Jacques, V., Magnetometry with nitrogen-vacancy defects in diamond. Rep. Prog. Phys. 2014, 77 (5), 056503.

2. Schirhagl, R.; Chang, K.; Loretz, M.; Degen, C. L., Nitrogen-Vacancy Centers in Diamond: Nanoscale Sensors for Physics and Biology. Annu. Rev. Phys. Chem. 2014, 65 (1), 83-105.

3. Rosskopf, T.; Dussaux, A.; Ohashi, K.; Loretz, M.; Schirhagl, R.; Watanabe, H.; Shikata, S.; Itoh, K. M.; Degen, C. L., Investigation of Surface Magnetic Noise by Shallow Spins in Diamond. Phys. Rev. Lett. 2014, 112 (14), 147602.

4. Wrachtrup, J.; Jelezko, F.; Grotz, B.; McGuinness, L., Nitrogen-vacancy centers close to surfaces. MRS Bulletin 2013, 38 (02), 149-154.



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  • FEIT Building, CB04.05.430
  • 81 Broadway
  • 81 Broadway, Ultimo NSW 2007, New South Wales
  • Australia 2007
  • Building: 11
  • Room Number: CB04.05.430
  • Co-sponsored by IBMD Seminar Series


  Speakers

Dr Alastair Stacey

Topic:

Sensing real world systems with quantum defects in diamond at room temperature

Dr Alastair Stacey from
University of Melbourne