低溫下電子氣體的熱容量.pdf

1、上海交通大學碩士學位論文低溫下電子氣體的熱容量姓名：郭凌偉申請學位級別：碩士專業(yè)：理論物理指導教師：徐宏華2002.2.1ABSTRACTInthecalculationofthespecificheatoftheelectrongasithasbeentheproblemthattheTInTtermduetoexchangeoccursatlowtemperature[1】whichisnotacceptableduetOtheli

2、neardependenceontemperatureoftheelectronicspecificheatobservedinexperiments[2】Inrecentstudies[3】theTInTproblemwasreinvestigatedanditwasfoundthatitcanbecancelledbytakingintoaccounttheanomalousdiagrams[4]Themainpurposeofth

3、epresentthesisistoshowthatthislogarithmicsingularityisnotessentialandcanberesolvedbytheclosed—pathGreenlSfunctionapproachinasimpleandtransparentwaywithoutresorttOanomalousdiagramsBesides，itprovidesanexamplewiththisspecia

4、lproblemtodemonstratesometechnicaladvantagesofthisreal—timeGreen’sfunctionapproachovertheimaginary—timeonewhichmaybehelpfulforinterestedreaders：withhelpofcausalityrelations(ietherelationsamongtimeorderedGreenlSfunctions)

5、，theclosed—pathapproachcanbeutilizedtoderivephysicalexpressionsofasysteminasimpleandgeneralwayand，insomecases，maybringupevennovelresultswhicharehardlyobtainablefortheimaginary—timeapproachbymeansofanalyticalcontinuations