English
Related papers

Related papers: Global Control Methods for GHZ State Generation on…

200 papers

We explore reachable sets of open $n$-qubit quantum systems, the coherent parts of which are under full unitary control and that have just one qubit whose Markovian noise amplitude can be modulated in time such as to provide an additional…

Quantum Physics · Physics 2015-03-20 V. Bergholm , T. Schulte-Herbrueggen

The control laws based on quantum Lyapunov control method are designed to prepare operators for two level open quantum systems in this paper. A novel Lyapunov function is proposed according to a matrix logarithm function. The higher…

Mathematical Physics · Physics 2018-08-15 Jie Wen , Shuang Cong

Preparing quantum states across many qubits is necessary to unlock the full potential of quantum computers. However, a key challenge is to realize efficient preparation protocols which are stable to noise and gate imperfections. Here, using…

Adiabatic gauge potential is the origin of nonadiabatic transitions. In counterdiabatic driving, which is a method of shortcuts to adiabaticity, adiabatic gauge potential can be used to realize identical dynamics to adiabatic time evolution…

Quantum Physics · Physics 2021-01-27 Takuya Hatomura , Kazutaka Takahashi

We demonstrate a method of adiabatic population transfer from a single quantum state into a coherent superposition of states. The transfer is executed with femtosecond pulses, spectrally shaped in simple and intuitive manner, which does not…

Quantum Physics · Physics 2015-05-14 S. Zhdanovich , E. A. Shapiro , J. W. Hepburn , M. Shapiro , V. Milner

We implement and characterize a protocol that enables arbitrary local controls in a dipolar atom array, where the degree of freedom is encoded in a pair of Rydberg states. Our approach relies on a combination of local addressing beams and…

By means of optimal control techniques we model and optimize the manipulation of the external quantum state (center-of-mass motion) of atoms trapped in adjustable optical potentials. We consider in detail the cases of both non interacting…

Quantum annealing is a novel type of analog computation that aims to use quantum mechanical fluctuations to search for optimal solutions of Ising problems. Quantum annealing in the transverse field Ising model, implemented on D-Wave…

Quantum Physics · Physics 2023-06-13 Elijah Pelofske

We show how a digitized version of Quantum Annealing can be made optimal, realizing the best possible solution allowed by quantum mechanics in the shortest time, without any prior knowledge on the location and properties of the spectral…

Quantum Physics · Physics 2019-11-28 Glen Bigan Mbeng , Rosario Fazio , Giuseppe E. Santoro

A stable and fast path linking two arbitrary states of a quantum system is generally required for state-engineering protocols, such as stimulated Raman adiabatic passage, shortcuts to adiabaticity, and holonomic transformation. Such a path…

Quantum Physics · Physics 2025-01-08 Zhu-yao Jin , Jun Jing

A systematic scheme is proposed to numerically estimate the quantum speed limit and temporal shape of optimal control in two-level and three-level quantum systems with bounded amplitude. For the two-level system, two quantum state…

Quantum Physics · Physics 2023-05-02 Xikun Li

Suppose a quantum system starts to evolve under a Hamiltonian from some initial state. When for the first time, will an observable attain a preassigned value? To answer this question, one method often adopted is to make instantaneous…

Quantum Physics · Physics 2016-06-01 Shrabanti Dhar , Subinay Dasgupta

The ability to accurately control a quantum system is a fundamental requirement in many areas of modern science such as quantum information processing and the coherent manipulation of molecular systems. It is usually necessary to realize…

One of the difficulties in adiabatic quantum computation is the limit on the computation time. Here we propose two schemes to speed-up the adiabatic evolution. To apply this controlled adiabatic evolution to adiabatic quantum computation,…

Quantum Physics · Physics 2015-05-14 W. Wang , S. C. Hou , X. X. Yi

The preparation of ground states of spin systems is a fundamental operation in quantum computing and serves as the basis of adiabatic quantum computing. This form of quantum computation is subject to the adiabatic theorem which in turn…

Quantum Physics · Physics 2022-03-02 Andreas Hartmann , Glen Bigan Mbeng , Wolfgang Lechner

By developing the preceding work on the fast forward of transient phenomena of quantum tunneling by Khujakulov and Nakamura (Phys. Rev. {\bf A 93}, 022101 (2016) ), we propose a scheme of the exact fast forward of adiabatic control of…

Quantum Physics · Physics 2017-06-14 Katsuhiro Nakamura , Anvar Khujakulov , Sanat Avazbaev , Shumpei Masuda

Quantum adiabatic passages can be greatly accelerated by a suitable control field, called a counter-diabatic field, which varies during the scan through resonance. Here, we implement this technique on the electron spin of a single…

An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective…

Quantum Physics · Physics 2008-10-22 Daoyi Dong , Chenbin Zhang , Herschel Rabitz , Alexander Pechen , Tzyh-Jong Tarn

We present a control scheme for quantum systems coupled to a thermal bath. We demonstrate state-to-state control between two Gibbs states. This scheme can be used to accelerate thermalization and cool the open system. Starting from a…

Quantum Physics · Physics 2021-03-11 Roie Dann , Ander Tobalina , Ronnie Kosloff

Control strategies for dissipative preparation of target quantum states, both pure and mixed, and subspaces are obtained by switching between a set of available semigroup generators. We show that the class of problems of interest can be…

Quantum Physics · Physics 2015-06-17 Pierre Scaramuzza , Francesco Ticozzi