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Related papers: Nonadiabatic ring-polymer instanton rate theory: a…

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We consider quantum tunnelling in asymmetric double-well systems for which the local minima in the two wells have the same energy, but the frequencies differ slightly. We derive a generalization of instanton theory for these asymmetric…

Chemical Physics · Physics 2020-09-04 Elena Jahr , Gabriel Laude , Jeremy O. Richardson

We present a simple method for the calculation of reaction rates in the Fermi golden-rule limit, which accurately captures the effects of tunnelling and zero-point energy. The method is based on a modification of the recently proposed…

Chemical Physics · Physics 2020-10-23 Joseph E. Lawrence , David E. Manolopoulos

A novel treatment of non-adiabatic couplings is proposed. The derivation starts from the long-known, but not well-known, fact that the wave function of the complete system of elctrons and nuclei can be written, without approximation, as a…

Materials Science · Physics 2007-05-23 Nikitas I. Gidopoulos , E. K. U. Gross

Adiabatic invariants are introduced and shown to provide an approximate second integral of motion for the non-integrable Dicke model, in the energy region where the system exhibits a regular dynamics. This low-energy region is always…

An adiabatic-connection fluctuation-dissipation theorem approach based on a range separation of electron-electron interactions is proposed. It involves a rigorous combination of short-range density functional and long-range random phase…

Materials Science · Physics 2009-03-03 Julien Toulouse , Iann C. Gerber , Georg Jansen , Andreas Savin , János G. Ángyán

The exact nuclear time-dependent potential energy surface arises from the exact decomposition of electronic and nuclear motion, recently presented in [A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. 105, 123002 (2010)]. Such…

Chemical Physics · Physics 2015-06-16 Federica Agostini , Ali Abedi , Yasumitsu Suzuki , E. K. U. Gross

We develop a scheme of fast forward of adiabatic spin dynamics of quantum entangled states. We settle the quasi-adiabatic dynamics by adding the regularization terms to the original Hamiltonian and then accelerate it with use of a large…

Quantum Physics · Physics 2018-05-25 Iwan Setiawan , Bobby Eka Gunara , Shumpei Masuda , Katsuhiro Nakamura

Quantum annealing is a continuous-time heuristic quantum algorithm for solving or approximately solving classical optimization problems. The algorithm uses a schedule to interpolate between a driver Hamiltonian with an easy-to-prepare…

The accuracy of rate constants calculated using transition state theory depends crucially on the correct identification of a recrossing--free dividing surface. We show here that it is possible to define such optimal dividing surface in…

The quantum kinetic framework provides a versatile method for investigating the dynamical optical and transport currents of crystalline solids. In this paper, starting from the density-matrix equations of motion, we present a general…

Mesoscale and Nanoscale Physics · Physics 2023-05-05 Pankaj Bhalla , Kamal Das , Amit Agarwal , Dimitrie Culcer

Shortcuts to adiabaticity is a general method for speeding up adiabatic quantum protocols, and has many potential applications in quantum information processing. Unfortunately, analytically constructing shortcuts to adiabaticity for systems…

Quantum Physics · Physics 2021-07-13 F. Setiawan , Peter Groszkowski , Hugo Ribeiro , Aashish A. Clerk

We revisit the implementation of a two-qubit entangling gate, the M{\o}lmer-S{\o}rensen gate, using the adiabatic Rydberg dressing paradigm for neutral atoms as studied in [Phys. Rev. A 101, 030301 (R) (2020)]. We study the implementation…

Motivated by experiments with current biased superconducting atomic point contacts the general problem of nonadiabatic transitions between adiabatic surfaces in presence of strong dissipation is studied. For a single channel device the…

Mesoscale and Nanoscale Physics · Physics 2009-06-05 Hans Fritz , Joachim Ankerhold

The Born-Oppenheimer approximation leads to the counterintuitive result of a vanishing electronic flux density upon vibrational dynamics in the electronic ground state. To circumvent this long known issue, we propose using pairwise…

Quantum Physics · Physics 2016-04-26 Vincent Pohl , Jean Christophe Tremblay

We present a state-space-based path integral method to calculate the rate of electron transfer (ET) in multi-state, multi-electron condensed-phase processes. We employ an exact path integral in discrete electronic states and continuous…

Chemical Physics · Physics 2016-06-07 Jessica Ryan Duke , Nandini Ananth

An accurate theory describing adiabatic following of the dark, nonabsorbing state in the three-level system is developed. An analytical solution for the wave function of the particle experiencing Raman excitation is found as an expansion in…

Optics · Physics 2009-11-10 R. N. Shakhmuratov , J. Odeurs

The ring polymer molecular dynamics (RPMD) rate theory is an efficient and accurate method for estimating rate coefficients of chemical reactions affected by nuclear quantum effects. The commonly used RPMD treatment of gas-phase bimolecular…

Chemical Physics · Physics 2025-04-03 Chen Li , Liang Zhang , Bin Jiang , Hua Guo

We present a new quantum adiabatic theorem that allows one to rigorously bound the adiabatic timescale for a variety of systems, including those described by unbounded Hamiltonians. Our bound is geared towards the qubit approximation of…

Quantum Physics · Physics 2024-01-17 Evgeny Mozgunov , Daniel A. Lidar

Entanglement distribution between trapped-atom quantum memories, viz. single atoms in optical cavities, is addressed. In most scenarios, the rate of entanglement distribution depends on the efficiency with which the state of traveling…

Quantum Physics · Physics 2013-05-29 Mohsen Razavi , Jeffrey H. Shapiro

Adiabatic protocols are often employed in state preparation schemes but require the system to be driven by a slowly varying Hamiltonian so that transitions between instantaneous eigenstates are exponentially suppressed. Counterdiabatic…

Quantum Physics · Physics 2024-03-20 Callum W. Duncan