Superradiant Quantum Phase Transition for an Exactly Solvable Two-Qubit Spin-Boson Model

Grimaudo, Roberto; Valenti, Davide; Sergi, Alessandro; Messina, A.

doi:10.3390/e25020187

Cited by 11 publications

(13 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hereinafter, we take a = 1. For an adiabatically varying magnetic field, one needs to choose α 1, when the model coincides with the Landau-Majorana-Stuckelberg-Zener (LMSZ) model [27][28][29][30] widely used in various problems with a time-dependent Hamiltonian [12,[31][32][33][34][35].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Pseudo-Qutrit Formed by Two Interacting Identical Spins (s = 1/2) in a Variable External Magnetic Field

Belousov

Igor

Vladimir

2023

Entropy

View full text Add to dashboard Cite

An analytical solution is obtained for the problem of two interacting, identical but separated spin 1/2 particles in a time-dependent external magnetic field, in a general case. The solution involves isolating the pseudo-qutrit subsystem from a two-qubit system. It is shown that the quantum dynamics of a pseudo-qutrit system with a magnetic dipole–dipole interaction can be described clearly and accurately in an adiabatic representation, using a time-dependent basis set. The transition probabilities between the energy levels for an adiabatically varying magnetic field, which follows the Landau–Majorana–Stuckelberg–Zener (LMSZ) model within a short time interval, are illustrated in the appropriate graphs. It is shown that for close energy levels and entangled states, the transition probabilities are not small and strongly depend on the time. These results provide insight into the degree of entanglement of two spins (qubits) over time. Furthermore, the results are applicable to more complex systems with a time-dependent Hamiltonian.

show abstract

Section: Discussionmentioning

confidence: 99%

“…The derivative for ϑ 2 is relatively cumbersome, and we will give some main intermediate relations. Firstly, using definition (35), we can write…”

Section: Conflicts Of Interestmentioning

confidence: 99%

Pseudo-Qutrit Formed by Two Interacting Identical Spins (s = 1/2) in a Variable External Magnetic Field

Belousov

Igor

Vladimir

2023

Entropy

View full text Add to dashboard Cite

show abstract

“…Introduction.-With the experimental advances into the era of ultra-strong coupling in light-matter interactions [1,2] and the theoretical efforts on the fundamental Quantum Rabi model (QRM) , finite-component quantum phase transitions (QPTs) have recently received an increasing attention [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Practical applications of the finite-component QPTs have been exploited in critical quantum metrology and quantum information science [39][40][41][42][43][44][45].…”

mentioning

confidence: 99%

“…By varying the coupling strength, the ground state of the system changes abruptly from the normal phase (NP) to the supperadiant phase (SP) with a boost of photon number. Due to this exotic behavior, the SPT has been widely studied [5][6][7][8][9][10][11][12][13][14][15][16][17][18][50][51][52][53][54][55][56]. Besides the Dicke model, the QRM [30-32, 57, 58], describing the interaction between a single TLS (with level splitting Ω) and a single-mode field (with frequency ω), can also predict the SPT in the low-frequency limit (i.e., ω/Ω → 0) as a replacement of thermodynamic limit [5][6][7][8][9][10][11][12][13][14][15][16][17][18]59].…”

mentioning

confidence: 99%

“…Due to this exotic behavior, the SPT has been widely studied [5][6][7][8][9][10][11][12][13][14][15][16][17][18][50][51][52][53][54][55][56]. Besides the Dicke model, the QRM [30-32, 57, 58], describing the interaction between a single TLS (with level splitting Ω) and a single-mode field (with frequency ω), can also predict the SPT in the low-frequency limit (i.e., ω/Ω → 0) as a replacement of thermodynamic limit [5][6][7][8][9][10][11][12][13][14][15][16][17][18]59]. Both the Dicke model and the QRM can be experimentally realized in cavity quantum electrodynamics (CQED) or circuit systems [1,2,[60][61][62][63][64].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Switchable Superradiant Phase Transition with Kerr Magnons

Liu¹,

Xiong²,

Ying³

2023

Preprint

View full text Add to dashboard Cite

The superradiant phase transition (SPT) has been widely studied in cavity quantum electrodynamics (CQED). However, this SPT is still subject of ongoing debates due to the no-go theorem induced by the so-called A 2 term (AT). We propose a hybrid quantum system, consisting of a singlemode cavity simultaneously coupled to both a two-level system and yttrium-iron-garnet sphere supporting magnons with Kerr nonlinearity, to restore the SPT against the AT. The Kerr magnons here can effectively introduce an additional strong and tunable AT to counteract the intrinsic AT, via adiabatically eliminating the degrees of freedom of the magnons. We show that the Kerr magnons induced SPT can exist in both cases of ignoring and including the intrinsic AT. Without the intrinsic AT, the critical coupling strength can be dramatically reduced by introducing the Kerr magnons, which greatly relaxes the experimental conditions for observing the SPT. With the intrinsic AT, the forbidden SPT can be recovered with the Kerr magnons in a reversed way. Our work paves a potential way to manipulate the SPT against the AT in hybrid systems combining CQED and nonlinear magnonics.

show abstract

Robust Topological Feature against Non‐Hermiticity in Jaynes–Cummings Model

Ying

2024

Adv Quantum Tech

View full text Add to dashboard Cite

The Jaynes–Cummings Model (JCM) is a fundamental model and building block for light‐matter interactions, quantum information and quantum computation. The present work analytically analyzes the topological feature manifested by the JCM in the presence of non‐Hermiticity which may arise from dissipation and decay rates. Indeed, the eigenstates of the JCM are topologically characterized by spin windings in 2D plane. The non‐Hermiticity tilts the spin‐winding plane and induces an out‐of‐plane component, while the topological feature is maintained. In particular, besides the invariant spin texture nodes, the study reveals a non‐Hermiticity‐induced reversal transition of the tilting angle and spin winding direction with a fractional phase gain at gap closing, a partially level‐independent reversal transition without gap closing, and a completely level‐independent super‐invariant point with untilted angle and also without gap closing. The result demonstrates that the topological feature is robust against non‐Hermiticity, which may be favorable in practical applications. On the other hand, one may conversely make use of the disadvantageous dissipation and decay rates to reverse the spin winding direction, which may add a controlled way for topological manipulation of quantum systems in light‐matter interactions.

show abstract

Superradiant Quantum Phase Transition for an Exactly Solvable Two-Qubit Spin-Boson Model

Cited by 11 publications

References 90 publications

Pseudo-Qutrit Formed by Two Interacting Identical Spins (s = 1/2) in a Variable External Magnetic Field

Pseudo-Qutrit Formed by Two Interacting Identical Spins (s = 1/2) in a Variable External Magnetic Field

Switchable Superradiant Phase Transition with Kerr Magnons

Robust Topological Feature against Non‐Hermiticity in Jaynes–Cummings Model

Contact Info

Product

Resources

About