Ergodicity breaking and deviation from eigenstate thermalization in relativistic quantum field theory

Srdinšek, Miha (avtor), Prosen, Tomaž (avtor), Sotiriadis, Spyros (avtor)

The validity of the ergodic hypothesis in quantum systems can be rephrased in the form of the eigenstate thermalization hypothesis (ETH), a set of statistical properties for the matrix elements of local observables in energy eigenstates, which is expected to hold in any ergodic system. We test the ETH in a nonintegrable model of relativistic quantum field theory (QFT) using the numerical method of Hamiltonian truncation in combination with analytical arguments based on Lorentz symmetry and renormalization group theory. We find that there is an infinite sequence of eigenstates with the characteristics of quantum many-body scars—that is, exceptional eigenstates with observable expectation values that lie far from thermal values—and we show that these states are one-quasiparticle states. We argue that in the thermodynamic limit the eigenstates cover the entire area between two diverging lines: the line of one-quasiparticle states, whose direction is dictated by relativistic kinematics, and the thermal average line. Our results suggest that the strong version of the ETH is violated in any relativistic QFT whose spectrum admits a quasiparticle description.

• Jezik: Angleški jezik
• Ključne besede: statistical physics, eigenstate thermalization, quantum field theory
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Različica publikacije: Recenzirani rokopis
• Datum objave: 12.01.2024
• Leto izida: 2024
• Št. strani: Str. 021601-1-021601-7
• Številčenje: Vol. 132, iss. 2
• PID: 20.500.12556/RUL-155535
• UDK: 536.93
• ISSN pri članku: 0031-9007
• DOI: 10.1103/PhysRevLett.132.021601
• COBISS.SI-ID: 191511299
• Datum objave v RUL: 05.04.2024

Gradivo je del revije

• Naslov: Physical review letters
• Skrajšan naslov: Phys. rev. lett.
• Založnik: American Physical Society
• ISSN: 0031-9007
• COBISS.SI-ID: 1282575

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: statistična fizika, termalizacija lastnih stanj, kvantna teorija polja

Projekti

• Financer: EC - European Commission
• Program financ.: European Commission
• Številka projekta: 101030988
• Naslov: Tensor Network Truncated Conformal Space Approach
• Akronim: TNTCSA

• Financer: ARIS - Javna agencija za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije
• Številka projekta: P1-0402-2019
• Naslov: Matematična fizika