Non-invasive Micro-nano Structures Measurement Based On Nitrogen-vacancy Centers In Diamond

In the information age,the application of micro-nano structures is ubiquitous,such as transistors and micro-electro mechanical sensors.With the development of science and technology,newer types of micro-nano structures are exploiting constantly.It re-quires to measure micro-nano structures in order to guide the research and develop-ment process.At present,common methods to measure micro-nano structures are op-tical techniques,such as optical microscope,ellipsometry and non-optical techniques,such as electron microscope,atomic force microscope(AFM).An advantage of optical method is using the light as a probe to detect the sample non-destructively.However,the resolution of optical method is low.Comparing with the optical method,the resolu-tion of electron microscope and AFM is very high.However,the electron microscope needs vacuum environment and the tip of AFM is easy to destroy the sample.These methods cannot observe the internal structure of the sample.The sample has to be cut open to observe the internal structure.It is a destructive method.To solve these problems,researchers are exploiting new measurement methods constantly.With the development of quantum information,especially the establish-ment of quantum metrology,it offers a platform to overcome these problems by using quantum system or quantum phenomenon to detect micro-nano structures.Due to stable fluorescence and long coherence time at room temperature,nitrogen vacancy(NV)cen-ter in diamond plays an important role in the field of quantum computing and quantum sensing.The properties of chemically stable and non-toxic of diamond make NV cen-ter suitable for the measurement of living cell.Since the sample's property is obtained by detecting NV centers' fluorescence signal,therefore,the sample can be measured without damage.In this thesis,micro-nano structures were detected by NV centers in diamond non-invasively.1.The structure of silver film was measured using NV centers in diamond.When the thickness of silver film is less than the electron mean free path in bulk silver,the dielectric constant is dependent on the thickness of silver film,which makes the surface plasmon to be thickness dependent.By detecting the modification of NV centers' fluo-rescence lifetime with surface plasmon,the thickness information of silver film can be obtained.2.The silver nanowire sample was imaged by NV centers in diamond.The differ-ence in surface plasmon between single nanowire and nanowire dimers was measured.The super-resolution microscope based on charge state depletion was used in the exper-iment to detected the signal,which cannot be recognized in confocal microscope.The electric current of nanowire sample can also be imaged based on the optically detected magnetic resonance of NV centers in diamond.Although super-resolution microscope has many benefits,the power of laser is usually very high.The strong laser can damage the sample in experiment.Therefore,we proposed a super-resolution method based on pulsed laser excitation to reduce the average laser power.3.The "Johnson noise" of gold,silver and titanium film was probed by longitudi-nal spin relaxation lifetime(T1)of NV centers.The results indicated that the "Johnson noise" was stronger with the higher conductivity of metal film at the same film thick-ness.Furthermore,we measured T1 of NV centers with various thickness of silver film.The T1 decreased continuously with the range of thickness from 20 nm to 400 nm.To intuitively show the difference between optical and electric property of silver film,we fabricated relief structure with the thickness of 70 nm and 400 nm.The relief struc-ture was clear when using T1-magnetometry imaging,while it was hard to recognize the relief structure by probing the fluorescence of NV centers.This indicated that three dimensional measurement can be realized by detecting T1.Through these researches,we had a deeper understanding of the nature and appli-cations of NV centers in diamond,and mastered relevant measurement methods.Some conclusions were obtained in the measurement of micro-nano structures by NV centers in diamond.As an outstanding solid state quantum system,NV centers in diamond will play a more important role in the development of new types of material and micro-nano structures in the future.