Theory of Two-Qubit $T_2$ Spectroscopy of Quantum Many-Body Systems

• URL: http://arxiv.org/abs/2603.18176v1
• Date: Wed, 18 Mar 2026 18:20:41 GMT
• Title: Theory of Two-Qubit $T_2$ Spectroscopy of Quantum Many-Body Systems
• Abstract summary: We show how suitable pulse applied to a twoqubit sensor enable separate extraction of the response and noise of a probed environment.<n>As a complementary application, we demonstrate that the method clearly distinguishes between different transport regimes in the system.
• Score: 0.05131152350448099
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Multi-qubit quantum sensors are rapidly emerging as platforms that extend the capabilities of conventional single-qubit sensing. In this work we show how suitable pulse sequences applied to a two-qubit sensor enable separate extraction of the response and noise of a probed environment within a $T_2$ spectroscopy framework. By resorting to representative examples, we demonstrate that this approach can resolve the spatio-temporal spreading of correlations in a many-body system. In particular, the resulting correlated dephasing signal captures features such as the dispersion of low-energy excitations, which manifest as light-cone-like profiles in the propagation of correlations. We further show that non-equilibrium conditions, for instance those induced by external driving, can modify this profile by producing additional fringes outside the light-cone. As a complementary application, we demonstrate that the method clearly distinguishes between different transport regimes in the system, including ballistic spreading, diffusive broadening, and the crossover between them.

Related papers

• Accurate noise spectroscopy using quantum sensing ensembles [70.36032466145112]
  We present an analysis procedure for accessing the true source noise spectrum using ensemble coherence.<n>We show that sequence timing plays a dual role in ensemble noise spectroscopy, setting both the frequency selectivity and the weighted collection of signal.<n>We apply this procedure to a model system, shallow nitrogen-vacancy centres in diamond, and show that consistent information about the spectral character of MHz-range surface noise can be obtained.
  arXiv  Detail & Related papers  (2026-09-15T05:03:36Z)
• Revisiting Spectral Representations in Generative Diffusion Models [98.43552218868837]
  Diffusion models have shown remarkable performance on diverse generation tasks.<n>Recent work finds that imposing representation alignment on the hidden states of diffusion networks can both facilitate training convergence and enhance sampling quality.<n>We investigate the connection between self-supervised spectral representation learning and diffusion generative models through a shared perspective on perturbation kernels.
  arXiv  Detail & Related papers  (2026-09-08T04:54:02Z)
• Dissipative Spectroscopy [4.527618005279638]
  We introduce dissipative spectroscopy as a framework for extracting spectral information from quantum systems via controlled dissipation.<n>We show that the DS can identify two-particle soft modes near quantum critical points and, on the normal-phase side, predict the emergence of macroscopic order exhibiting power-law growth following a dissipation quench.
  arXiv  Detail & Related papers  (2026-02-16T08:35:11Z)
• Unveiling photon-photon coupling induced transparency and absorption [0.0]
  This study presents the theoretical foundations of an analogous electromagnetically induced transparency (EIT) and absorption (EIA) respectively. We provide a concise phenomenological description with analytical expressions for transmission spectra and dispersion elucidating how the interplay of coherent and dissipative interactions in a coupled system results in the emergence of level repulsion and attraction, corresponding to CIT and CIA, respectively.
  arXiv  Detail & Related papers  (2024-06-28T09:18:30Z)
• Process tensor approaches to modeling two-dimensional spectroscopy [0.0]
  We present a numerical method to model optical spectra of non-Markovian open quantum systems. To demonstrate the efficacy of our method, we compare 2D electronic spectroscopy simulations produced through our method to Markovian master equation simulations.
  arXiv  Detail & Related papers  (2024-02-23T17:29:57Z)
• Entanglement-enhanced dual-comb spectroscopy [0.7340017786387767]
  Dual-comb interferometry harnesses the interference of two laser frequency combs to provide unprecedented capability in spectroscopy applications. We propose an entanglement-enhanced dual-comb spectroscopy protocol that leverages quantum resources to significantly improve the signal-to-noise ratio performance. Our results show significant quantum advantages in the uW to mW power range, making this technique particularly attractive for biological and chemical sensing applications.
  arXiv  Detail & Related papers  (2023-04-04T03:57:53Z)
• Macroscopic noise amplification by asymmetric dyads in non-Hermitian optical systems for generative diffusion models [55.2480439325792]
  asymmetric non-Hermitian dyads are promising candidates for efficient sensors and ultra-fast random number generators. integrated light emission from such asymmetric dyads can be efficiently used for all-optical degenerative diffusion models of machine learning.
  arXiv  Detail & Related papers  (2022-06-24T10:19:36Z)
• Exact solutions of interacting dissipative systems via weak symmetries [77.34726150561087]
  We analytically diagonalize the Liouvillian of a class Markovian dissipative systems with arbitrary strong interactions or nonlinearity. This enables an exact description of the full dynamics and dissipative spectrum. Our method is applicable to a variety of other systems, and could provide a powerful new tool for the study of complex driven-dissipative quantum systems.
  arXiv  Detail & Related papers  (2021-09-27T17:45:42Z)
• Quantum asymmetry and noisy multi-mode interferometry [55.41644538483948]
  Quantum asymmetry is a physical resource which coincides with the amount of coherence between the eigenspaces of a generator. We show that the asymmetry may emphincrease as a result of a emphdecrease of coherence inside a degenerate subspace.
  arXiv  Detail & Related papers  (2021-07-23T07:30:57Z)
• Two-photon resonance fluorescence of two interacting non-identical quantum emitters [77.34726150561087]
  We study a system of two interacting, non-indentical quantum emitters driven by a coherent field. We show that the features imprinted by the two-photon dynamics into the spectrum of resonance fluorescence are particularly sensitive to changes in the distance between emitters. This can be exploited for applications such as superresolution imaging of point-like sources.
  arXiv  Detail & Related papers  (2021-06-04T16:13:01Z)
• Probing particle-particle correlation in harmonic traps with twisted light [0.0]
  We explore the potential of twisted light as a tool to unveil many-body effects in parabolically confined systems. We demonstrate the ability of the proposed twisted light probe to capture the transition of interacting fermions into a strongly correlated regime. These features, observed in exact calculations for two electrons, are reproduced in adiabatic Time Dependent Density Functional Theory simulations.
  arXiv  Detail & Related papers  (2021-05-12T16:07:59Z)
• Observation-dependent suppression and enhancement of two-photon coincidences by tailored losses [68.8204255655161]
  Hong-Ou-Mandel (HOM) effect can lead to a perfect suppression of two-particle coincidences between the output ports of a balanced beam splitter. In this work, we demonstrate experimentally that the two-particle coincidence statistics of two bosons can instead be seamlessly tuned to substantial enhancement. Our findings reveal a new approach to harnessing non-Hermitian settings for the manipulation of multi-particle quantum states.
  arXiv  Detail & Related papers  (2021-05-12T06:47:35Z)
• Tuning photon statistics with coherent fields [0.0]
  Photon correlations, as measured by Glauber's $n$-th order coherence functions, are highly sought to be minimized and/or maximized. In systems that are coherently driven, so-called blockades can give rise to strong correlations according to two scenarios. We show how these two approaches relate to the admixing of a coherent state with a quantum state.
  arXiv  Detail & Related papers  (2020-04-24T17:50:40Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.