Acoustic analog of Hawking radiation in quantized circular superflows of Bose-Einstein condensates

Abstract

We propose emulation of Hawking radiation (HR) by means of acoustic excitations propagating on top of persistent current in an atomic Bose-Einstein condensate (BEC) loaded in an annular confining potential. The setting is initially created as a spatially uniform one, and then switches into a nonuniform configuration, while maintaining uniform BEC density. The eventual setting admits the realization of sonic black and white event horizons with different slopes of the local sound speed. A smooth slope near the white-hole horizon suppresses instabilities in the supersonic region. It is found that tongue-shaped patterns of the density-density correlation function, which represent the acoustic analog of HR, are strongly affected by the radius of the ring-shaped configuration and number of discrete acoustic modes admitted by it. There is a minimum radius that enables the emulation of HR. We also briefly discuss a possible similarity of properties of the matter-wave sonic black holes to the known puzzle of the stability of Planck-scale primordial black holes in quantum gravity.

Engineering phase and density of Bose–Einstein condensates in curved waveguides with toroidal topology

“…The confinement provided by the potential barrier surrounding the vortex core makes even multi-charged (q > 1) metastable vortex states highly robust. The generation and stability of these atomic flows in condensates with toroidal topology have been extensively explored both experimentally [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] and theoretically [48][49][50][51][52][53][54][55][56][57][58][59]. These investigations have revealed their topological protection in the absence of external driving, highlighting their robust nature.…”

Analogue Gravitational Lensing in Bose-Einstein Condensates

“…Subsequently, the field has witnessed impressive development both theoretically and experimentally, expanding beyond sonic waves in classical fluids. Among these achievements, we can mention phonons in Bose-Einstein condensates [4][5][6][7][8][9][10][11][12][13][14][15][16], surface waves on water flows [17][18][19][20][21], slow light in optical systems [22][23][24][25][26][27][28][29], and magnons in magnetic systems [30,31]. These analogue systems have become an important testing ground for certain aspects of curved spacetimes, especially those involving quantum systems where the superradiance effect [20,32], Hawking radiation [6][7][8]11], and cosmological particle production [12][13][14] are present.…”

“…Among these achievements, we can mention phonons in Bose-Einstein condensates [4][5][6][7][8][9][10][11][12][13][14][15][16], surface waves on water flows [17][18][19][20][21], slow light in optical systems [22][23][24][25][26][27][28][29], and magnons in magnetic systems [30,31]. These analogue systems have become an important testing ground for certain aspects of curved spacetimes, especially those involving quantum systems where the superradiance effect [20,32], Hawking radiation [6][7][8]11], and cosmological particle production [12][13][14] are present. Furthermore, analogue gravity can provide insights into the quantum nature of gravity while aiding in understanding the spacetime back-reaction [33,34] and the cosmological constant problem [35].…”

Analogue gravitational lensing in optical Bose-Einstein condensates

“…Since then, the field witnessed an impressive development, both theoretically and experimentally, expanding beyond sonic waves in classical fluids. Among these achievements, we can cite phonons in Bose-Einstein condensates [4][5][6][7][8][9][10][11], surface waves in water flows [12][13][14][15], slow light in optical systems [16][17][18][19][20][21] and magnons in magnetic systems [22,23]. These analogue systems have become an important testing ground for some aspects of general relativity, while providing insights for the quantum nature of gravity [24,25].…”