92 citations · 620 across the 21 of their papers we have counts for
22 papers
Superradiant and subradiant states in lifetime-limited organic molecules through laser-induced tuning
Christian Lange, Emma Daggett, Valentin Walther +2
An array of radiatively coupled emitters is an exciting new platform for generating, storing, and manipulating quantum light. However, the simultaneous positioning and tuning of mu…
Quantum light from lossy semiconductor Rydberg excitons
Valentin Walther, Anders S. Sørensen
The emergence of photonic quantum correlations is typically associated with emitters strongly coupled to a photonic mode. Here, we show that semiconductor Rydberg excitons, which a…
Realizing distance-selective interactions in a Rydberg-dressed atom array
Simon Hollerith, Kritsana Srakaew, David Wei +10
Measurement-based quantum computing relies on the rapid creation of large-scale entanglement in a register of stable qubits. Atomic arrays are well suited to store quantum informat…
Microwave-optical coupling via Rydberg excitons in cuprous oxide
Liam A. P. Gallagher, Joshua P. Rogers, Jon D. Pritchett +9
We report exciton-mediated coupling between microwave and optical fields in cuprous oxide (CuO) at low temperatures. Rydberg excitonic states with principal quantum number up t…
Superglass formation in an atomic BEC with competing long-range interactions
Stefan Ostermann, Valentin Walther, Susanne F. Yelin
The complex dynamical phases of quantum systems are dictated by atomic interactions that usually evoke an emergent periodic order. Here, we study a quantum many-body system with tw…
Photon control and coherent interactions via lattice dark states in atomic arrays
Oriol Rubies-Bigorda, Valentin Walther, Taylor L. Patti +1
Ordered atomic arrays with subwavelength spacing have emerged as an efficient and versatile light-matter interface, where emitters respond collectively and form subradiant lattice…
Simulation of many-body dynamics using Rydberg excitons
Jacob Taylor, Sumit Goswami, Valentin Walther +3
The recent observation of high-lying Rydberg states of excitons in semiconductors with relatively high binding energy motivates exploring their applications in quantum nonlinear op…
Correlated many-body noise and emergent behavior in an anharmonic fluctuator model
P N Thomas Lloyd, Valentin Walther, Hossein Sadeghpour
Fluctuating electric fields emanating from surfaces are a primary source of decoherence in trapped ion qubits. Here, we show that superradiant phonon-induced excitation exchange be…
Nonclassical Light from Exciton Interactions in a Two-Dimensional Quantum Mirror
Valentin Walther, Lida Zhang, Susanne F. Yelin +1
Excitons in a semiconductor monolayer form a collective resonance that can reflect resonant light with extraordinarily high efficiency. Here, we investigate the nonlinear optical p…
Photon-photon interactions in Rydberg-atom arrays
Lida Zhang, Valentin Walther, Klaus Mølmer +1
We investigate the interaction of weak light fields with two-dimensional lattices of atoms, in which two-photon coupling establishes conditions of electromagnetically induced trans…
Self-bound droplet clusters in laser-driven Bose-Einstein condensates
Yong-Chang Zhang, Valentin Walther, Thomas Pohl
We investigate a two-dimensional Bose-Einstein condensate that is optically driven via a retro-reflecting mirror, forming a single optical feedback loop. This induces a peculiar ty…
Asymmetric Rydberg blockade of giant excitons in Cuprous Oxide
Julian Heckötter, Valentin Walther, Stefan Scheel +3
The ability to generate and control strong long-range interactions via highly excited electronic states has been the foundation for recent breakthroughs in a host of areas, from at…
Electromagnetically induced transparency with CuO excitons in the presence of phonon coupling
Valentin Walther, Peter Grünwald, Thomas Pohl
Highly excited Rydberg states of excitons in CuO semiconductors provide a promising approach to explore and control strong particle interactions in a solid-state environment. A…
Plasma-enhanced interaction and optical nonlinearities of CuO Rydberg excitons
Valentin Walther, Thomas Pohl
We theoretically investigate the nonlinear optical transmission through a cuprous oxide crystal for wavelengths that cover the series of highly excited excitons, observed in recent…
Enhanced nonlinear interaction of polaritons via excitonic Rydberg states in monolayer WSe2
Jie Gu, Valentin Walther, Lutz Waldecker +7
Strong optical nonlinearities play a central role in realizing quantum photonic technologies. In solid state systems, exciton-polaritons, which result from the hybridization of mat…
Blockade-induced resonant enhancement of the optical nonlinearity in a Rydberg medium
Annika Tebben, Clément Hainaut, Valentin Walther +4
We predict a resonant enhancement of the nonlinear optical response of an interacting Rydberg gas under conditions of electromagnetically induced transparency. The enhancement orig…
Quantum gas microscopy of Rydberg macrodimers
Simon Hollerith, Johannes Zeiher, Jun Rui +6
A microscopic understanding of molecules is essential for many fields of natural sciences but their tiny size hinders direct optical access to their constituents. Rydberg macrodime…
Interactions between Rydberg excitons in CuO
Valentin Walther, Sjard Ole Krüger, Stefan Scheel +1
Highly-excited states of excitons in cuprous oxide have recently been observed at a record quantum number of up to . Here, we evaluate the long-range interactions between pai…
Long-range interactions and symmetry-breaking in quantum gases through optical feedback
Yong-Chang Zhang, Valentin Walther, Thomas Pohl
We consider a quasi two-dimensional atomic Bose Einstein condensate interacting with a near-resonant laser field that is back-reflected onto the condensate by a planar mirror. We s…
Giant optical nonlinearities from Rydberg-excitons in semiconductor microcavities
Valentin Walther, Robert Johne, Thomas Pohl
The realization of exciton-polaritons -- hybrid excitations of semiconductor quantum well excitons and cavity photons -- has been of great technological and scientific significance…
Maximum caliber is a general variational principle for nonequilibrium statistical mechanics
Michael J. Hazoglou, Valentin Walther, Purushottam D. Dixit +1
There has been interest in finding a general variational principle for non-equilibrium statistical mechanics. We give evidence that Maximum Caliber (Max Cal) is such a principle. M…
Attractor Metadynamics in Adapting Neural Networks
Claudius Gros, Mathias Linkerhand, Valentin Walther
Slow adaption processes, like synaptic and intrinsic plasticity, abound in the brain and shape the landscape for the neural dynamics occurring on substantially faster timescales. A…