We calculate the dynamic vortex mass for clean Fermi superfluids including both $s$ - and $d$ -wave superconductors as a response to a vortex acceleration. Assuming a finite quasiparticle mean free time, the vortex mass appears to be a tensor with components depending on the quasiparticle relaxation time. The diagonal component dominates in the limit of long mean free time while the off-diagonal mass takes over in the moderately clean regime.We calculate the dynamic vortex mass for clean Fermi superfluids including both $s$- and $d$-wave superconductors as a response to a vortex acceleration. Assuming a finite quasiparticle mean free time, the vortex mass appears to be a tensor with components depending on the quasiparticle relaxation time. The diagonal component dominates in the limit of long mean free time while the off-diagonal mass takes over in the moderately clean regime.

arXiv:cond-mat/9806065Physical Review LettersNov 2, 1998111 citations

Quasiparticle Interactions in Many-Body Systems

J. Ruvalds

Springer eBooksJan 1, 19760 citations

Non-Poissonian Quantum Jumps of a Fluxonium Qubit due to Quasiparticle Excitations

Uri Vool, Ioan M. Pop, Katrina Sliwa +12 more

As the energy relaxation time of superconducting qubits steadily improves, nonequilibrium quasiparticle excitations above the superconducting gap emerge as an increasingly relevant limit for qubit coherence. We measure fluctuations in the number of quasiparticle excitations by continuously monitoring the spontaneous quantum jumps between the states of a fluxonium qubit, in conditions where relaxation is dominated by quasiparticle loss. Resolution on the scale of a single quasiparticle is obtained by performing quantum nondemolition projective measurements within a time interval much shorter than T₁, using a quantum-limited amplifier (Josephson parametric converter). The quantum jump statistics switches between the expected Poisson distribution and a non-Poissonian one, indicating large relative fluctuations in the quasiparticle population, on time scales varying from seconds to hours. This dynamics can be modified controllably by injecting quasiparticles or by seeding quasiparticle-trapping vortices by cooling down in a magnetic field.As the energy relaxation time of superconducting qubits steadily improves, nonequilibrium quasiparticle excitations above the superconducting gap emerge as an increasingly relevant limit for qubit coherence. We measure fluctuations in the number of quasiparticle excitations by continuously monitoring the spontaneous quantum jumps between the states of a fluxonium qubit, in conditions where relaxation is dominated by quasiparticle loss. Resolution on the scale of a single quasiparticle is obtained by performing quantum nondemolition projective measurements within a time interval much shorter than T₁, using a quantum-limited amplifier (Josephson parametric converter). The quantum jump statistics switches between the expected Poisson distribution and a non-Poissonian one, indicating large relative fluctuations in the quasiparticle population, on time scales varying from seconds to hours. This dynamics can be modified controllably by injecting quasiparticles or by seeding quasiparticle-trapping vortices by cooling down in a magnetic field.

arXiv:1406.1769Physical Review LettersDec 8, 2014142 citations

Thermal diffusivity above the Mott-Ioffe-Regel limit

Jiecheng Zhang, Erik D. Kountz, Eli M. Levenson-Falk +3 more

Understanding transport of charge excitations in strongly correlated electron systems exhibiting the ``strange metal'' state without long-lived quasiparticle excitations has been a long-standing challenge in condensed matter physics. Here, the authors demonstrate that thermal diffusivity, which tracks energy-thermalization processes, exhibits a limiting Planckian relaxation time and a unique thermal diffusion velocity. These reflect both the contribution of phonons and electrons. This result is bound by the thermal diffusivity of the electrons at the Mott-Ioffe-Regel limit, where the mean-free-path reaches atomic distances.Understanding transport of charge excitations in strongly correlated electron systems exhibiting the ``strange metal'' state without long-lived quasiparticle excitations has been a long-standing challenge in condensed matter physics. Here, the authors demonstrate that thermal diffusivity, which tracks energy-thermalization processes, exhibits a limiting Planckian relaxation time and a unique thermal diffusion velocity. These reflect both the contribution of phonons and electrons. This result is bound by the thermal diffusivity of the electrons at the Mott-Ioffe-Regel limit, where the mean-free-path reaches atomic distances.

arXiv:1808.07564Physical review. B./Physical review. BDec 24, 201935 citations

Avoided quasiparticle decay from strong quantum interactions

Ruben Verresen, Roderich Moessner, Frank Pollmann

arXiv:1810.01422Nature PhysicsMay 27, 201980 citations

We calculate the dynamic vortex mass for clean Fermi superfluids including both

s

- and

d

-wave superconductors as a response to a vortex acceleration. Assuming a finite quasiparticle mean free time, the vortex mass appears to be a tensor with components depending on the quasiparticle relaxation time. The diagonal component dominates in the limit of long mean free time while the off-diagonal mass takes over in the moderately clean regime.