7 papers
Extracting the pairing gap from van Hove singularities in rf spectra of the Fermi Hubbard model
Chuping Li, Kaichao Zhang, Junru Wu +5
We show that van Hove singularities in rf spectra of the 3D attractive Fermi Hubbard model provide a robust route to extracting the pairing gap. Four types of singularities are cla…
Criterion for qubit-assisted quantum metrology approaching Heisenberg scaling
Peng Chen, Jun Jing
We study in this work the metrology precision of a probe system coupled to an ancillary qubit. Restricting the probe-qubit coupling along only one or two directions is found to be…
Rf spectra and pseudogap in ultracold Fermi gases across the BCS-BEC crossover from pairing fluctuation theory
Chuping Li, Lin Sun, Kaichao Zhang +5
The pseudogap phenomenon is a hallmark of strongly interacting Fermi systems, from high-temperature superconductors to ultracold atomic gases, yet its precise origin remains debate…
Spectral study of the pseudogap in unitary Fermi gases
Chuping Li, Lin Sun, Kaichao Zhang +5
The existence of a pseudogap in unitary Fermi gases has recently been established and measured experimentally [Li et al., Nature 626, 288 (2024)]. This lends strong support for the…
Precision limit under weak coupling with an ancillary qubit
Peng Chen, Jun Jing
We propose a measurement-based quantum metrology protocol in a composite model, where the probe system (a spin ensemble) is coupled to an ancillary two-level system (qubit) with a…
Achieving the Heisenberg limit of metrology via measurement on an ancillary qubit
Peng Chen, Jun Jing
In the scenario of the probe-ancilla interaction, we propose a quantum metrology protocol by the unconditional measurement on the ancillary qubit after an optimized period of joint…