Theory Research Of High Fidelity Quantum Operation In Solid-state Spin System

In recent years,more and more people focus on the field of quantum computers.This is because,on the one hand,quantum computer has its own unique computing advantage and has an overwhelming computing advantage over some unique problems compared to the classic computer.On the other hand,the classical Moore's law has come to an end.There are two main contents in this paper.One is the simulation and calculation of semiconductor quantum dots,which is an important alternative to quantum computers.A scheme to solve high fidelity quantum operations is proposed.The other aspect is to study the solid-state quantum storage of rare earth doped crystals,and put forward a super long entangled time and stable solid state storage scheme.The main contents of this article include:1.From the perspective of quantum mechanics,the main features and difficulties of quantum computers are briefly introduced.2.We introduce the solid-state quantum solution.One is a semiconductor quantum dot.The quantum dot is equivalent to making a person made atom by the existing processing technology.This artificial atom has a special energy level structure and can be used as qubit for quantum computation.Quantum dots can be made into multiple quantum dots,so quantum computers will not be dreams.3.An important alternative for solid-state quantum memory is introduced.The quantum memory made with doped rare earth crystals has a long coherent time,and the loss in the transmission process is very satisfactory.This platform can also help the research of quantum information and quantum mechanics.4.The electrical control pulses are carefully designed in combination with the characteristics of the geometric interference of the quantum bits of a semiconductor quantum dot,namely the intrinsic anti-interference,and the non adiabatic logic gate operation of the single and multi bits has been completed.To a certain extent,one of the core problems of the whole quantum computation is solved.In addition,we also studied the influence of noise on fidelity in decoherence process,and its relationship with fidelity of quantum computation is also very important.5.Through the study of the structure and energy level of quantum dots,the full line control pulse is designed in combination with certain experimental data.The controllable adiabatic operation is completed.This result is also high fidelity,both single and multi bits,showing the advantage of quantum control.The essence of this scheme is to change the rate of variation at a very low rate in time,and change the timing of control pulse in a timely manner.Such a control pulse is easy to implement,showing its advantages over other high fidelity pulses.6.We discuss the logic gate operation using fast adiabatic in the coherent time aiming at the single and two bits in the quantum dots.In this process,the quantum operation is fast and stable,and of course it is a high fidelity process.The relationship between the duration of each operation and the intensity and fidelity of the stimulus pulse used to control is also discussed.For quantum computation,we choose the most of the current experimental group,each has its advantages and disadvantages.We analyze and give simulation data.7.In the spin photon mixed qubit system,the exact decoupling pulse operation for spin qubit is performed and the results are simulated.The conclusion is that the quantum operation of decoherence protection can be obtained.Photon as information and carrier,thanks to high fidelity,our method is also effective for the preparation of photon states.8.Ihe doping of rare earth crystals is used to simulate solid-state quantum memories and explain their related properties.Under the interaction of the near Y library spin and the central Eu ion,the spin dynamics of the library is significantly suppressed.The implementation of the dynamic decoupling sequence combines its inherent slow library dynamics,and expresses the characteristics on the coherent time and the coherent envelope,which has a long coherent time that can reach a number of hours,and the coherence time is also found in the experiment.In addition,it also has a long time of high fidelity,high efficiency,spin state,combined with its multimode ability,the doped rare earth crystals in the solid-state quantum memory scheme is bound to have superior performance.The main innovations in this paper are as follows:1.In geometric Landau-Zener-Stuckelberg(LZS)interferometry,a high fidelity non adiabatic universal logic gate operation is completed,and a theoretical model is provided.2.Aiming at the logic gate operation of semiconductor quantum dots,using the energy level structure in the semiconductor quantum dots,an easy to experiment pulse is designed.The pulse is easily made and applied,and the high fidelity logic gate calculation can be completed in theory.3.According to the operation scheme used in various experiments,the characteristics of the numerical simulation are analyzed.The accuracy and speed of the calculation are given,and the data and chart are demonstrated.4.A decoupling pulse scheme capable of providing decoherence protection is provided for mixed bits,and the numerical simulation results are provided.5.The solid-state quantum memory with doped rare-earth crystals is simulated and its unique library dynamics is explained and used,and the coherence time of the quantum memory is extended to the hour scale by combining our own decoupling sequence.