176 citations · 512 across the 18 of their papers we have counts for
17 papers · 1 filter
Quantum machine learning with glow for episodic tasks and decision games
Jens Clausen, Hans J. Briegel
We consider a general class of models, where a reinforcement learning (RL) agent learns from cyclic interactions with an external environment via classical signals. Perceptual inpu…
Time-optimal bath-induced unitaries by Zermelo navigation: speed limit and non-Markovian quantum computation
Jens Clausen
The solution of the quantum Zermelo navigation problem is applied to the non-Markovian open system dynamics of a set of quantum systems interacting with a common environment. We co…
Multiple re-encounter approach to radical pair reactions and the role of nonlinear master equations
Jens Clausen, Gian Giacomo Guerreschi, Markus Tiersch +1
We formulate a multiple-encounter model of the radical pair mechanism that is based on a random coupling of the radical pair to a minimal model environment. These occasional pulse-…
Task-dependent control of open quantum systems
Jens Clausen, Guy Bensky, Gershon Kurizki
We develop a general optimization strategy for performing a chosen unitary or non-unitary task on an open quantum system. The goal is to design a controlled time-dependent system H…
Dynamical control of quantum state transfer within hybrid open systems
B. M. Escher, G. Bensky, J. Clausen +2
We analyze quantum state-transfer optimization within hybrid open systems, from a "noisy" (write-in) qubit to its "quiet" counterpart (storage qubit). Intriguing interplay is revea…
Analog control of open quantum systems under arbitrary decoherence
Jens Clausen, Guy Bensky, Gershon Kurizki
We derive and investigate a general non-Markovian equation for the time-dependence of a Hamiltonian that maximizes the fidelity of a desired quantum gate on any finite-dimensional…
Linear optics substituting scheme for multi-mode operations
J. Clausen, L. Knoell, D. -G. Welsch
We propose a scheme allowing a conditional implementation of suitably truncated general single- or multi-mode operators acting on states of traveling optical signal modes. The sche…
Entanglement purification of multi-mode quantum states
J Clausen, L Knoell, D-G Welsch
An iterative random procedure is considered allowing an entanglement purification of a class of multi-mode quantum states. In certain cases, a complete purification may be achieved…
Purification and detection of entangled coherent states
J. Clausen, L. Knoell, D. -G. Welsch
In [J. C. Howell and J. A. Yeazell, Phys. Rev. A 62, 012102 (2000)], a proposal is made to generate entangled macroscopically distinguishable states of two spatially separated trav…
Quantum state conversion by cross-Kerr interaction
J. Clausen, L. Knoell, D. -G. Welsch
A generalized Mach-Zehnder-type interferometer equipped with cross-Kerr elements is proposed to convert N-photon truncated single-mode quantum states into (N+1)-mode single-photon…
Conditional quantum state engineering in repeated 2-photon down conversion
J. Clausen, H. Hansen, L. Knoll +2
The U(1,1) and U(2) transformations realized by three-mode interaction in the respective parametric approximations are studied in conditional measurement, and the corresponding non…
Conditional teleportation using optical squeezers and photon counting
J. Clausen, T. Opatrny, D. -G. Welsch
We suggest a scheme of using two-mode squeezed vacuum for conditional teleportation of quantum states of optical field. Alice mixes the input state with one of the squeezed modes o…
Measuring quantum state overlaps of traveling optical fields
J. Clausen, M. Dakna, L. Knoll +1
We propose a detection scheme for measuring the overlap of the quantum state of a weakly excited traveling-field mode with a desired reference quantum state, by successive mixing t…
Conditional quantum state engineering at beam splitter arrays
J. Clausen, M. Dakna, L. Knoell +1
The generation of arbitrary single-mode quantum states from the vacuum by alternate coherent displacement and photon adding as well as the measurement of the overlap of a signal wi…
Conditional quantum-state transformation at a beam splitter
J. Clausen, M. Dakna, L. Knoll +1
Using conditional measurement on a beam splitter, we study the transformation of the quantum state of the signal mode within the concept of two-port non-unitary transformation. All…
Generation of arbitrary quantum states of traveling fields
M. Dakna, J. Clausen, L. Knoll +1
We show that any single-mode quantum state can be generated from the vacuum by alternate application of the coherent displacement operator and the creation operator. We propose an…
Generating and monitoring Schrödinger cats in conditional measurement on a beam splitter
M. Dakna, J. Clausen, L. Knoll +1
Preparation of Schrödinger-cat-like states via conditional output measurement on a beam splitter is studied. In the scheme, a mode prepared in a squeezed vacuum is mixed with a mod…