Detecting optical signatures of quantum phase transitions (QPT) in driven-dissipative systems constitutes a new frontier for many-body physics. Here we propose a practical idea to characterize the extensively studied phenomenon of photonic QPT, based on a many-body system composed of nitrogen-vacancy centers embedded individually in photonic crystal cavities, by detecting the critical behaviors of mean photon number, photon fluctuation, photon correlation, and emitted spectrum. Our results bridge these observables to the distinct optical signatures in different quantum phases and serve as good indicators and invaluable tools for studying dynamical properties of dissipative QPT.Detecting optical signatures of quantum phase transitions (QPT) in driven-dissipative systems constitutes a new frontier for many-body physics. Here we propose a practical idea to characterize the extensively studied phenomenon of photonic QPT, based on a many-body system composed of nitrogen-vacancy centers embedded individually in photonic crystal cavities, by detecting the critical behaviors of mean photon number, photon fluctuation, photon correlation, and emitted spectrum. Our results bridge these observables to the distinct optical signatures in different quantum phases and serve as good indicators and invaluable tools for studying dynamical properties of dissipative QPT.

arXiv:1904.06291Optics LettersApr 11, 20194 citations

Robust approach to study the effect on quantum phase transitions of various perturbations at finite temperatures

Cheng-Pu Lv, Yanchao Li, Hai‐Qing Lin

We propose using maximum coherence ( ${\mathrm{QC}}_{\mathrm{max}}$ ) to study quantum phase transition (QPT). We investigate several well-known models, such as the XXZ model, ${J}_{1}\text{\ensuremath{-}}{J}_{2}$ model, and one-dimensional spin Kitaev model. The results show that ${\mathrm{QC}}_{\mathrm{max}}$ can be used to detect different types of QPTs, including the Berezinskii-Kosterlitz-Thouless and topological types. In addition, ${\mathrm{QC}}_{\mathrm{max}}$ is more robust against interferences, such as thermal fluctuations and measurement interferences, than any existing detector. This property enables ${\mathrm{QC}}_{\mathrm{max}}$ to identify QPTs in experiments, where temperature effects and measurement interferences always exist. Thus, ${\mathrm{QC}}_{\mathrm{max}}$ might be an ideal tool for studying QPTs because of its measurability, universality, and robustness against interferences.We propose using maximum coherence (${\mathrm{QC}}_{\mathrm{max}}$) to study quantum phase transition (QPT). We investigate several well-known models, such as the XXZ model, ${J}_{1}\text{\ensuremath{-}}{J}_{2}$ model, and one-dimensional spin Kitaev model. The results show that ${\mathrm{QC}}_{\mathrm{max}}$ can be used to detect different types of QPTs, including the Berezinskii-Kosterlitz-Thouless and topological types. In addition, ${\mathrm{QC}}_{\mathrm{max}}$ is more robust against interferences, such as thermal fluctuations and measurement interferences, than any existing detector. This property enables ${\mathrm{QC}}_{\mathrm{max}}$ to identify QPTs in experiments, where temperature effects and measurement interferences always exist. Thus, ${\mathrm{QC}}_{\mathrm{max}}$ might be an ideal tool for studying QPTs because of its measurability, universality, and robustness against interferences.

Physical review. B./Physical review. BFeb 22, 20225 citations

Practical Guide to Quantum Phase Transitions in Superconducting Quantum Dots

A. Kadlecová, Martin Žonda, Vladislav Pokorný +1 more

Jul 18, 20180 citations

Studies of Semiconductor Quantum Dots for Quantum Information Processing

Huan Song, Tatsuya Usuki

Springer eBooksNov 29, 20071 citation

Probing quantum phase transitions in a spin chain with a double quantum dot

Yun-Pil Shim, Sangchul Oh, Jianjia Fei +2 more

Quantum phase transitions (QPTs) in qubit systems are known to produce singularities in the entanglement, which could in turn be used to probe the QPT. Recent proposals have suggested that the QPT in a spin chain could be probed via the entanglement between external qubits coupled to the spin chain. Such experiments may be technically challenging, because the probe qubits are nonlocal. Here we show that a double quantum dot coupled locally to a spin chain provides an alternative and efficient probe of a QPT. To demonstrate this method in a simple geometry, we propose an experiment to observe a QPT in a triple quantum dot, based on the well-known singlet projection technique.Quantum phase transitions (QPTs) in qubit systems are known to produce singularities in the entanglement, which could in turn be used to probe the QPT. Recent proposals have suggested that the QPT in a spin chain could be probed via the entanglement between external qubits coupled to the spin chain. Such experiments may be technically challenging, because the probe qubits are nonlocal. Here we show that a double quantum dot coupled locally to a spin chain provides an alternative and efficient probe of a QPT. To demonstrate this method in a simple geometry, we propose an experiment to observe a QPT in a triple quantum dot, based on the well-known singlet projection technique.

arXiv:1209.5445Physical Review BApr 8, 20133 citations

We propose using maximum coherence (

{\mathrm{QC}}_{\mathrm{max}}

) to study quantum phase transition (QPT). We investigate several well-known models, such as the XXZ model, ${J}_{1}\text{\ensuremath{-}}{J}_{2}$ model, and one-dimensional spin Kitaev model. The results show that

{\mathrm{QC}}_{\mathrm{max}}

can be used to detect different types of QPTs, including the Berezinskii-Kosterlitz-Thouless and topological types. In addition,

{\mathrm{QC}}_{\mathrm{max}}

is more robust against interferences, such as thermal fluctuations and measurement interferences, than any existing detector. This property enables

{\mathrm{QC}}_{\mathrm{max}}

to identify QPTs in experiments, where temperature effects and measurement interferences always exist. Thus,

{\mathrm{QC}}_{\mathrm{max}}

might be an ideal tool for studying QPTs because of its measurability, universality, and robustness against interferences.