5 papers · 1 filter
Quantum Process Tomography of a Thermal Alkali-Metal Vapor
Yujie Sun, Marek Kopciuch, Arash Dezhang Fard +1
Characterizing the open-system dynamics of multilevel quantum systems (qudits) remains a fundamental challenge due to ensemble inhomogeneities and complex environmental interaction…
Liouvillian and Hamiltonian exceptional points of atomic vapors: The spectral signatures of quantum jumps
Marek Kopciuch, Adam Miranowicz
We investigate spectral singularities in an alkali-metal atomic vapor modeled using four and effectively three hyperfine states. By comparing the eigenvalue spectra of a non-Hermit…
Isolating Pure Quadratic Zeeman Splitting
Arash Dezhang Fard, Marek Kopciuch, Yujie Sun +2
Nonlinear magnetic interactions provide access to complex quantum spin dynamics and thus enable the study of intriguing physical phenomena. However, these interactions are often do…
Perfect quantum protractors
Michał Piotrak, Marek Kopciuch, Arash Dezhang Fard +3
In this paper we introduce and investigate the concept of a perfect quantum protractor, a pure quantum state that generates three different orthogonal bas…
Optimized experimental optical tomography of quantum states of room-temperature alkali-metal vapor
Marek Kopciuch, Magdalena Smolis, Adam Miranowicz +1
We demonstrate a novel experimental technique for quantum-state tomography of the collective density matrix. It is based on measurements of the polarization of light, traversing th…