EntityQ3591812· pop 5· linked from 19 articlesKMS stateSign in to savemixed state describing a system in thermal equilibriumConnectionsquantum mechanicsEntitythermodynamicsEntitydigital object identifierEntityInternational Standard Serial NumberEntityquantum field theoryEntityJulian SchwingerEntitycomplex analysisEntitystatistical mechanicsEntityphase changeEntityHilbert spaceEntitybibcodeEntityUniversity of WarsawEntityconservation lawEntityexpectationEntityHamiltonian operatorEntityanalytic functionEntityQ22908627Entityspontaneous symmetry breakingEntitydensity matrixEntityGreen's functionEntityCategoriesPhysics articles needing expert attentionQuantum field theoryQuantum statesStatistical mechanics