TY - JOUR
T1 - Quasiparticle lifetime in a two-dimensional electron system in the limit of low temperature and excitation energy
AU - Menashe, D.
AU - Laikhtman, B.
PY - 1996
Y1 - 1996
N2 - We study theoretically the quasiparticle lifetime, due to Coulomb scattering, in a two-dimensional electron system. It has long been established that in the limit of low excitation energy and temperature, the inverse lifetime behaves as (Formula presented)(p)∝(Δ/(Formula presented)(Formula presented)ln((Formula presented)/Δ), where Δ≡max(|(Formula presented)-(Formula presented)|,(Formula presented)). This result has been obtained in the leading order of the Coulomb interaction. We show that higher-order terms in the interaction contribute higher-order logarithmic factors, meaning that a correct theory must sum up all orders of the interaction. After performing this summation, using the Keldysh diagram technique, we find that the renormalized lifetime still has the same general form as above. On the other hand we find that only forward scattering contributes to the lifetime, whereas, in leading-order theory, both forward and backward scattering make a contribution (a similar result has already been obtained for the two-dimensional Hubbard model). This leads to a different proportionality constant for the lifetime. Because we employ the Keldysh diagram technique, we are also able to give an expression for the collision operator, which can be used in the study of near-equilibrium processes.
AB - We study theoretically the quasiparticle lifetime, due to Coulomb scattering, in a two-dimensional electron system. It has long been established that in the limit of low excitation energy and temperature, the inverse lifetime behaves as (Formula presented)(p)∝(Δ/(Formula presented)(Formula presented)ln((Formula presented)/Δ), where Δ≡max(|(Formula presented)-(Formula presented)|,(Formula presented)). This result has been obtained in the leading order of the Coulomb interaction. We show that higher-order terms in the interaction contribute higher-order logarithmic factors, meaning that a correct theory must sum up all orders of the interaction. After performing this summation, using the Keldysh diagram technique, we find that the renormalized lifetime still has the same general form as above. On the other hand we find that only forward scattering contributes to the lifetime, whereas, in leading-order theory, both forward and backward scattering make a contribution (a similar result has already been obtained for the two-dimensional Hubbard model). This leads to a different proportionality constant for the lifetime. Because we employ the Keldysh diagram technique, we are also able to give an expression for the collision operator, which can be used in the study of near-equilibrium processes.
UR - http://www.scopus.com/inward/record.url?scp=0000520195&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.54.11561
DO - 10.1103/PhysRevB.54.11561
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:0000520195
SN - 1098-0121
VL - 54
SP - 11561
EP - 11574
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 16
ER -