KROTOV METHOD FOR OPTIMAL CONTROL IN CLOSED QUANTUM SYSTEMS O. V. Morzhin1 and A. N. Pechen2 April 30, 2019 1 Steklov Mathematical Institute of Russian Academy of Sciences (Moscow), Senior Re- searcher. E-mail:
[email protected] 2 Steklov Mathematical Institute of Russian Academy of Sciences (Moscow), Head of the Department of Mathematical Methods for Quantum Technologies; National University of Science and Technology “MISIS” (Moscow), Department of Mathematics, Leading Re- searcher. E-mail:
[email protected] (corresponding author) Dedicated to the bright memory of Prof. Vadim F. Krotov AMS 2010 Mathematics Subject Classification. Primary 81Q93; Secondary 49Mxx, 35Q40, 93C15 UDC 517.958 Abstract Mathematical problems of optimal control in quantum systems attract high interest in connection with fundamental questions and existing and prospective applications. An important problem is the development of methods for constructing controls for quantum systems. One of the commonly used methods is the Krotov method initially proposed beyond quantum control in the articles by V.F. Krotov and I.N. Feldman (1978, 1983). The method was used to develop a novel approach for finding optimal controls for quan- tum systems in [D.J. Tannor, V. Kazakov, V. Orlov, In: Time-Dependent Quantum Molecular Dynamics, Boston, Springer, 347–360 (1992)] and [J. Soml´oi,V.A. Kaza- kov, D.J. Tannor, Chem. Phys., 172:1, 85–98 (1993)], and in many works of various scientists, as described in details in this review. The review discusses mathematical aspects of this method for optimal control of closed quantum systems. It outlines var- ious modifications with respect to defining the improvement function (which in most cases is linear or linear-quadratic), constraints on control spectrum and on the states of a quantum system, regularizers, etc.