Lei Zhang

All Publications

• Multiorbital dynamical mean-field theory with a complex-time solver PHYSICAL REVIEW RESEARCH Yu, Y., Zhang, L., Gull, E., Cao, X., Dong, X. 2026; 8 (2)

  View details for DOI 10.1103/yqv4-4vjx

  View details for Web of Science ID 001765875500001

• Compact representation and long-time extrapolation of real-time data for quantum systems using the ESPRIT algorithm PHYSICAL REVIEW B Erpenbeck, A., Zhu, Y., Yu, Y., Zhang, L., Gerum, R., Goulko, O., Yang, C., Cohen, G., Gull, E. 2026; 113 (11)

  View details for DOI 10.1103/8vzv-y74m

  View details for Web of Science ID 001729008800001

• Minimal pole representation for spectral functions. The Journal of chemical physics Zhang, L., Erpenbeck, A., Yu, Y., Gull, E. 2025; 162 (21)

  Abstract

  Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is a ubiquitous problem in condensed matter physics, with applications ranging from quantum transport simulations to the simulation of strongly correlated electron systems. This paper introduces a method for obtaining a compact, approximate representation of these functions, based on their parameterization on the real axis and a given approximate precision. We show applications to typical spectral functions and results for structured and unstructured correlation functions of model systems.

  View details for DOI 10.1063/5.0273763

  View details for PubMedID 40459352

• Minimal pole representation and analytic continuation of matrix-valued correlation functions PHYSICAL REVIEW B Zhang, L., Yu, Y., Gull, E. 2024; 110 (23)

  View details for DOI 10.1103/PhysRevB.110.235131

  View details for Web of Science ID 001379646400003

• Green/WeakCoupling: Implementation of fully self-consistent finite-temperature many-body perturbation theory for molecules and solids COMPUTER PHYSICS COMMUNICATIONS Iskakov, S., Yeh, C., Pokhilko, P., Yu, Y., Zhang, L., Harsha, G., Abraham, V., Wen, M., Wang, M., Adamski, J., Chen, T., Gull, E., Zgid, D. 2025; 306

  View details for DOI 10.1016/j.cpc.2024.109380

  View details for Web of Science ID 001322266900001

• Steady-state properties of multi-orbital systems using quantum Monte Carlo JOURNAL OF CHEMICAL PHYSICS Erpenbeck, A., Blommel, T., Zhang, L., Lin, W., Cohen, G., Gull, E. 2024; 161 (9)

  View details for DOI 10.1063/5.0226253

  View details for Web of Science ID 001309375700012

• Feynman diagrammatics based on discrete pole representations: A path to renormalized perturbation theories PHYSICAL REVIEW B Gazizova, D., Zhang, L., Gull, E., LeBlanc, J. F. 2024; 110 (7)

  View details for DOI 10.1103/PhysRevB.110.075158

  View details for Web of Science ID 001302908700001

• Minimal pole representation and controlled analytic continuation of Matsubara response functions PHYSICAL REVIEW B Zhang, L., Gull, E. 2024; 110 (3)

  View details for DOI 10.1103/PhysRevB.110.035154

  View details for Web of Science ID 001275929800002

• Graphical representations and worm algorithms for the O(<i>N</i>) spin model COMMUNICATIONS IN THEORETICAL PHYSICS Liu, L., Zhang, L., Tan, X., Deng, Y. 2023; 75 (11)

  View details for DOI 10.1088/1572-9494/acfbdf

  View details for Web of Science ID 001123546300001

• Tensor train continuous time solver for quantum impurity models PHYSICAL REVIEW B Erpenbeck, A., Lin, W., Blommel, T., Zhang, L., Iskakov, S., Bernheimer, L., Nunez-Fernandez, Y., Cohen, G., Parcollet, O., Waintal, X., Gull, E. 2023; 107 (24)

  View details for DOI 10.1103/PhysRevB.107.245135

  View details for Web of Science ID 001170592200001

• Loop-Cluster Coupling and Algorithm for Classical Statistical Models. Physical review letters Zhang, L., Michel, M., Elçi, E. M., Deng, Y. 2020; 125 (20): 200603

  Abstract

  Potts spin systems play a fundamental role in statistical mechanics and quantum field theory and can be studied within the spin, the Fortuin-Kasteleyn (FK) bond or the q-flow (loop) representation. We introduce a Loop-Cluster (LC) joint model of bond-occupation variables interacting with q-flow variables and formulate an LC algorithm that is found to be in the same dynamical universality as the celebrated Swendsen-Wang algorithm. This leads to a theoretical unification for all the representations, and numerically, one can apply the most efficient algorithm in one representation and measure physical quantities in others. Moreover, by using the LC scheme, we construct a hierarchy of geometric objects that contain as special cases the q-flow clusters and the backbone of FK clusters, the exact values of whose fractal dimensions in two dimensions remain as an open question. Our work not only provides a unified framework and an efficient algorithm for the Potts model but also brings new insights into the rich geometric structures of the FK clusters.

  View details for DOI 10.1103/PhysRevLett.125.200603

  View details for PubMedID 33258631