We point out that the recent experiments at ETH on fermions in optical lattices, where a band ins... more We point out that the recent experiments at ETH on fermions in optical lattices, where a band insulator evolves continuously into states occupying many bands as the system is swept adiabatically across Feshbach resonance, have implications on a wide range of fundamental issues in condensed matter. We derive the effective Hamiltonian of these systems, obtain expressions for their energies and band populations, and point out the increasing quantum entanglement of the ground state during the adiabatic sweep. Our results also explains why only specific regions in k-space can be populated after the sweep as found in ref. .
Current experiments on different samples of twisted bilayer graphene (TBG) have found different s... more Current experiments on different samples of twisted bilayer graphene (TBG) have found different sets of insulating phases. Despite this diversity, many features of these insulating phases appear to be universal. They include the dispersion of Landau fans away from charge neutrality, a reduced Landau fan degeneracy from the expected value at charge neutrality, and the further reduction of this degeneracy when crossing an insulating phase with odd number of electrons in the superlattice unit cell. We point out that all these behaviors as well as the ferromagnetic behavior observed in some of the insulating states suggest an underlying "ideal" pattern, with different part of it realized in the different samples in different experiments. We further show that such pattern can be accounted for by a Hubbard like model for the superlattice augmented with a set of chemical potential dependent mean fields that break the symmetry of the eight internal degrees of freedoms successively. The simultaneous importance of Mott like physics and mean field physics may be a general feature of twisted 2D electronic materials with large superlattices, not necessarily confined to graphene.
The advances in cold atom experiments have allowed construction of confining traps in the form of... more The advances in cold atom experiments have allowed construction of confining traps in the form of curved surfaces. This opens up the possibility of studying quantum gases in curved manifolds. On closed surfaces, many fundamental processes are affected by the local and global properties, i.e. the curvature and the topology of the surface. In this paper, we study the problem of potential scattering on a spherical surface and discuss its difference with that on a 2D plane. For bound states with angular momentum m, their energies (Em) on a sphere are related to those on a 2D plane (−|Em,o|) as Em = −|Em,o| + E R m 2 −1 3 + O r 2 o R 2 , where E R =h 2 /(2M R 2), and R is the radius of the sphere. Due to the finite extent of the manifold, the phase shifts on a sphere at energies E ∼ E R differ significantly from those on a 2D plane. As energy E approaches zero, the phase shift in the planar case approaches 0, whereas in the spherical case it reaches a constant that connects the microscopic length scale to the largest length scale R.
The current efforts of studying many-body effects with spin-orbit coupling (SOC) using alkalimeta... more The current efforts of studying many-body effects with spin-orbit coupling (SOC) using alkalimetal atoms are impeded by the heating effects due to spontaneous emission. Here, we show that even for SOCs too weak to cause any heating, dramatic many-body effects can emerge in a onedimensional(1D) spin 1/2 Fermi gas provided the interaction is sufficiently repulsive. For weak repulsion, the effect of a weak SOC (with strength Ω) is perturbative. inducing a weak spin spiral (with magnitude proportional to Ω). However, as the repulsion g increases beyond a critical value (gc ∼ 1/Ω), the magnitude of the spin spiral rises rapidly to a value of order 1 (independent of Ω). Moreover, near g = +∞, the spins of neighboring fermions can interfere destructively due to quantum fluctuations of particle motion, strongly distorting the spin spiral and pulling the spins substantially away from the direction of the local field at various locations. These effects are consequences of the spin-charge separation in the strongly repulsive limit. They will also occur in other 1D quantum gases with higher spins.
Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a ... more Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a narrow barrier is studied. We show that in the limit where inelastic scattering time is much longer than the tunneling time, which can be achieved in practice, electrons can tunnel back and forth through the barrier continously, leading to an oscillating current in the absence of external drives. The oscillatory behavior is dictated by a tunneling gap in the energy spectrum. We shall discuss ways to generate oscillating currents and the phenomenon of natural "dephasing" between the tunneling currents of edge states. The noise spectra of these junctions are also studied. They contain singularites reflecting the existence of tunneling gaps as well as the inherent oscillation in the system.
We show that the density profile of a Fermi gas in rapidly rotating potential will develop promin... more We show that the density profile of a Fermi gas in rapidly rotating potential will develop prominent features reflecting the underlying Landau level like energy spectrum. Depending on the aspect ratio of the trap, these features can be a sequence of ellipsoidal volumes or a sequence of quantized steps.
In recent years, there is considerable experimental effort using cold atoms to study strongly cor... more In recent years, there is considerable experimental effort using cold atoms to study strongly correlated many-body systems[1-6]. One class of phenomena of particularly interests is quantum critical (QC) phenomena. While prevalent in many materials, these phenomena are notoriously difficult theoretical problems due to the vanishing of energy scales in QC region. So far, there are no systematic ways to deduce QC behavior of bulk systems from the data of trapped atomic gases. Here, we present a simple algorithm to use the experimental density profile to determine the T=0 phase boundary of bulk systems, as well as the scaling functions in QC regime. We also present another scheme for removing finite size effects of the trap. We demonstrate the validity of our schemes using exactly soluble models.
It has been a long sought goal of Quantum Simulation to find answers to long standing questions i... more It has been a long sought goal of Quantum Simulation to find answers to long standing questions in condensed matter physics. A famous example is the ground and the excitations of 2D Hubbard model with strong repulsion below half filling. The system is a doped antiferromagnet. It is of great interests because of its possible relation to high Tc superconductor. Theoretically, the fermion excitations of this model are believed to split up into holons and spinions, and a moving holon is believed to leave behind it a string of "wrong" spins that mismatch with the antiferromagnet background. Here, we show that the properties of the ground state wavefunction and the holon excitation of the 2D Hubbard model can be revealed in unprecedented detail using the technique of quantum interference in atomic physics. This is achieved by using quantum interference to measure the Marshall sign of the doped antiferromanget. The region of wrong Marshall sign directly reflects the spatial extent of fluctuating string attached to the holon.
The hydrodynamics equations of binary mixtures of Bose gases, Fermi gases, and mixtures of Bose a... more The hydrodynamics equations of binary mixtures of Bose gases, Fermi gases, and mixtures of Bose and Fermi gases in the presence of external potentials are derived. These equations can be applied to current experiments on mixtures of atomic gases confined in magnetic traps.
We show that the density profile of a Fermi gas in rapidly rotating potential will develop promin... more We show that the density profile of a Fermi gas in rapidly rotating potential will develop prominent features reflecting the underlying Landau level like energy spectrum. Depending on the aspect ratio of the trap, these features can be a sequence of ellipsoidal volumes or a sequence of quantized steps.
We prove a Lieb-Schultz-Mattis theorem for the quantum spin Hall effect (QSHE) in twodimensional ... more We prove a Lieb-Schultz-Mattis theorem for the quantum spin Hall effect (QSHE) in twodimensional π-flux models. In the presence of time reversal, U (1) charge conservation and magnetic translation (with π-flux per unit cell) symmetries, if a generic interacting Hamiltonian has a unique gapped symmetric ground state at half filling (i.e. an odd number of electrons per unit cell), it can only be a QSH insulator. In other words, a trivial Mott insulator is forbidden by symmetries at half filling. We further show that such a symmetry-enforced QSHE can be realized in cold atoms, by shaking an optical lattice and applying a time-dependent Zeeman field.
Realizing quantum Hall states in a fast rotating Bose gas is a long sought goal in cold atom rese... more Realizing quantum Hall states in a fast rotating Bose gas is a long sought goal in cold atom research. The effort is very challenging because Bose statistics fights against quantum Hall correlations. In contrast, Fermi statistics does not cause such conflict. Here, we show that by sweeping the integer quantum Hall states of a spin-1/2 Fermi gas across the Feshbach resonance from the BCS side to the BEC side at a "projection" rate similar to that in the "projection" experiment of fermion superfluid, these states can be "fused" into a bosonic quantum Hall states. A projection sweep means the pair association is sufficiently fast so that the center of mass of the pair remains unchanged in the process. We show that the fusion of integer fermion states with filling factor ν ↑ = ν ↓ = n will result in a bosonic Laughlin state and Pfaffian state for n = 1 and 2. The is due to a hidden property of the fermionic integer quantum Hall states-for any grouping of opposite spin into pairs, their centers of mass automatically assume a bosonic quantum Hall structure.
Motivated by the recent discoveries of spin-1 and spin-1/2 Bose gas, we have studied the general ... more Motivated by the recent discoveries of spin-1 and spin-1/2 Bose gas, we have studied the general structure of the Bose gases with arbitrary spin. A general method is developed to uncover the elementary building blocks of the angular momentum eigenstates, as well as the relations (or interactions) between them. Applications of this method to Bose gas with integer spins (f = 1, 2, 3) and half integer spins (f = 1/2, 3/2) reveal many surprising structures.
We propose a simple scheme for generating rotating atomic clusters in an optical lattice which pr... more We propose a simple scheme for generating rotating atomic clusters in an optical lattice which produces states with quantum Hall and spin liquid properties. As the rotation frequencies increases, the ground state of a rotating cluster of spin-1 Bose atoms undergoes a sequence of (spin and orbit) transitions, which terminates at an angular momentum L * substantially lower than that of the boson Laughlin state. The spin-orbit correlations reflect 'fermionization' of bosons facilitated by their spin degrees of freedom. We also show that the density of an expanding group of clusters has a scaling form which reveals the quantum Hall and the spin structure of a single cluster.
We consider the condensate wavefunction of a rapidly rotating two-component Bose gas with an equa... more We consider the condensate wavefunction of a rapidly rotating two-component Bose gas with an equal number of particles in each component. If the interactions between like and unlike species are very similar (as occurs for two hyperfine states of 87 Rb or 23 Na) we find that the two components contain identical rectangular vortex lattices, where the unit cell has an aspect ratio of √ 3, and one lattice is displaced to the center of the unit cell of the other. Our results are based on an exact evaluation of the vortex lattice energy in the large angular momentum (or quantum Hall) regime.
We show that, apart from a difference in scale, all of the surprising recently observed propertie... more We show that, apart from a difference in scale, all of the surprising recently observed properties of a degenerate Fermi gas near a Feshbach resonance persist in the high temperature Boltzmann regime. In this regime, the Feshbach resonance is unshifted. By sweeping across the resonance, a thermal distribution of bound states (molecules) can be reversibly generated. Throughout this process, the interaction energy is negative and continuous. We also show that this behavior must persist at lower temperatures unless there is a phase transition as the temperature is lowered. We rigorously demonstrate universal behavior near the resonance.
We show that the quantum evolution of a spin-1 Bose gas with nearly all bosons initially in the F... more We show that the quantum evolution of a spin-1 Bose gas with nearly all bosons initially in the Fz = 0 state has a "quantum carpet" spin-time structure with self-similar properties. The system continuously evolves into "multi-peaked" Schrödinger cat like states, returning occasionally to coherent structures, which leads to large number fluctuations (as seen in recent experiments). The self similar behavior allows one to reveal the quantum evolution as a set of peaks in the number probability distribution of a spin component at times much shorter than the quantum revival time. We also show that these features survive small number fluctuations among spin components up to a few percent.
At present, there is a worldwide effort to use cold atoms to simulate strongly correlated quantum... more At present, there is a worldwide effort to use cold atoms to simulate strongly correlated quantum many-body systems. It is hoped that these "simulations" will provide solutions to many unsolved problems. However, the relevant energy scales in most of these experiments are so small that one has to go to entropy regimes far below those achievable today. Here, we present a general scheme to extract entropy directly from the region of interest. The late stage of this process is equivalent to a continuous "evaporation", and is able to combat intrinsic heating of the system. For illustration, we show how to cool a weak coupling BCS superfluid (with Tc ∼ 10 −10 K) to 10 −11 K with this simple procedure, with entropy per particle as low as 5 × 10 −4 kB in the superfluid region.
We show that when the Fermi energy of a Fermi gas is much smaller than the intrinsic energy width... more We show that when the Fermi energy of a Fermi gas is much smaller than the intrinsic energy width of a Feshbach resonance, the system behaves like a Fermi gas with a contact potential. This in turn implies universality at resonance, and large fermionic pairs in the strongly interacting regime. Recent experiments of JILA[1] and MIT[2] turn out to be deep inside the universal regime, which explains the perfect fit of these experiments by the BEC-BCS crossover theory with contact potential[3]. We also show that rf spectrocopy can be used to map out the pair wavefunction directly.
At present, many laboratories are performing experiments to simulate theoretical models of strong... more At present, many laboratories are performing experiments to simulate theoretical models of strongly correlated systems using cold atoms in optical lattices, a program referred to as "Quantum Simulation"
We point out that the recent experiments at ETH on fermions in optical lattices, where a band ins... more We point out that the recent experiments at ETH on fermions in optical lattices, where a band insulator evolves continuously into states occupying many bands as the system is swept adiabatically across Feshbach resonance, have implications on a wide range of fundamental issues in condensed matter. We derive the effective Hamiltonian of these systems, obtain expressions for their energies and band populations, and point out the increasing quantum entanglement of the ground state during the adiabatic sweep. Our results also explains why only specific regions in k-space can be populated after the sweep as found in ref. .
Current experiments on different samples of twisted bilayer graphene (TBG) have found different s... more Current experiments on different samples of twisted bilayer graphene (TBG) have found different sets of insulating phases. Despite this diversity, many features of these insulating phases appear to be universal. They include the dispersion of Landau fans away from charge neutrality, a reduced Landau fan degeneracy from the expected value at charge neutrality, and the further reduction of this degeneracy when crossing an insulating phase with odd number of electrons in the superlattice unit cell. We point out that all these behaviors as well as the ferromagnetic behavior observed in some of the insulating states suggest an underlying "ideal" pattern, with different part of it realized in the different samples in different experiments. We further show that such pattern can be accounted for by a Hubbard like model for the superlattice augmented with a set of chemical potential dependent mean fields that break the symmetry of the eight internal degrees of freedoms successively. The simultaneous importance of Mott like physics and mean field physics may be a general feature of twisted 2D electronic materials with large superlattices, not necessarily confined to graphene.
The advances in cold atom experiments have allowed construction of confining traps in the form of... more The advances in cold atom experiments have allowed construction of confining traps in the form of curved surfaces. This opens up the possibility of studying quantum gases in curved manifolds. On closed surfaces, many fundamental processes are affected by the local and global properties, i.e. the curvature and the topology of the surface. In this paper, we study the problem of potential scattering on a spherical surface and discuss its difference with that on a 2D plane. For bound states with angular momentum m, their energies (Em) on a sphere are related to those on a 2D plane (−|Em,o|) as Em = −|Em,o| + E R m 2 −1 3 + O r 2 o R 2 , where E R =h 2 /(2M R 2), and R is the radius of the sphere. Due to the finite extent of the manifold, the phase shifts on a sphere at energies E ∼ E R differ significantly from those on a 2D plane. As energy E approaches zero, the phase shift in the planar case approaches 0, whereas in the spherical case it reaches a constant that connects the microscopic length scale to the largest length scale R.
The current efforts of studying many-body effects with spin-orbit coupling (SOC) using alkalimeta... more The current efforts of studying many-body effects with spin-orbit coupling (SOC) using alkalimetal atoms are impeded by the heating effects due to spontaneous emission. Here, we show that even for SOCs too weak to cause any heating, dramatic many-body effects can emerge in a onedimensional(1D) spin 1/2 Fermi gas provided the interaction is sufficiently repulsive. For weak repulsion, the effect of a weak SOC (with strength Ω) is perturbative. inducing a weak spin spiral (with magnitude proportional to Ω). However, as the repulsion g increases beyond a critical value (gc ∼ 1/Ω), the magnitude of the spin spiral rises rapidly to a value of order 1 (independent of Ω). Moreover, near g = +∞, the spins of neighboring fermions can interfere destructively due to quantum fluctuations of particle motion, strongly distorting the spin spiral and pulling the spins substantially away from the direction of the local field at various locations. These effects are consequences of the spin-charge separation in the strongly repulsive limit. They will also occur in other 1D quantum gases with higher spins.
Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a ... more Electron tunneling between quantum Hall systems on the same two dimensional plane separated by a narrow barrier is studied. We show that in the limit where inelastic scattering time is much longer than the tunneling time, which can be achieved in practice, electrons can tunnel back and forth through the barrier continously, leading to an oscillating current in the absence of external drives. The oscillatory behavior is dictated by a tunneling gap in the energy spectrum. We shall discuss ways to generate oscillating currents and the phenomenon of natural "dephasing" between the tunneling currents of edge states. The noise spectra of these junctions are also studied. They contain singularites reflecting the existence of tunneling gaps as well as the inherent oscillation in the system.
We show that the density profile of a Fermi gas in rapidly rotating potential will develop promin... more We show that the density profile of a Fermi gas in rapidly rotating potential will develop prominent features reflecting the underlying Landau level like energy spectrum. Depending on the aspect ratio of the trap, these features can be a sequence of ellipsoidal volumes or a sequence of quantized steps.
In recent years, there is considerable experimental effort using cold atoms to study strongly cor... more In recent years, there is considerable experimental effort using cold atoms to study strongly correlated many-body systems[1-6]. One class of phenomena of particularly interests is quantum critical (QC) phenomena. While prevalent in many materials, these phenomena are notoriously difficult theoretical problems due to the vanishing of energy scales in QC region. So far, there are no systematic ways to deduce QC behavior of bulk systems from the data of trapped atomic gases. Here, we present a simple algorithm to use the experimental density profile to determine the T=0 phase boundary of bulk systems, as well as the scaling functions in QC regime. We also present another scheme for removing finite size effects of the trap. We demonstrate the validity of our schemes using exactly soluble models.
It has been a long sought goal of Quantum Simulation to find answers to long standing questions i... more It has been a long sought goal of Quantum Simulation to find answers to long standing questions in condensed matter physics. A famous example is the ground and the excitations of 2D Hubbard model with strong repulsion below half filling. The system is a doped antiferromagnet. It is of great interests because of its possible relation to high Tc superconductor. Theoretically, the fermion excitations of this model are believed to split up into holons and spinions, and a moving holon is believed to leave behind it a string of "wrong" spins that mismatch with the antiferromagnet background. Here, we show that the properties of the ground state wavefunction and the holon excitation of the 2D Hubbard model can be revealed in unprecedented detail using the technique of quantum interference in atomic physics. This is achieved by using quantum interference to measure the Marshall sign of the doped antiferromanget. The region of wrong Marshall sign directly reflects the spatial extent of fluctuating string attached to the holon.
The hydrodynamics equations of binary mixtures of Bose gases, Fermi gases, and mixtures of Bose a... more The hydrodynamics equations of binary mixtures of Bose gases, Fermi gases, and mixtures of Bose and Fermi gases in the presence of external potentials are derived. These equations can be applied to current experiments on mixtures of atomic gases confined in magnetic traps.
We show that the density profile of a Fermi gas in rapidly rotating potential will develop promin... more We show that the density profile of a Fermi gas in rapidly rotating potential will develop prominent features reflecting the underlying Landau level like energy spectrum. Depending on the aspect ratio of the trap, these features can be a sequence of ellipsoidal volumes or a sequence of quantized steps.
We prove a Lieb-Schultz-Mattis theorem for the quantum spin Hall effect (QSHE) in twodimensional ... more We prove a Lieb-Schultz-Mattis theorem for the quantum spin Hall effect (QSHE) in twodimensional π-flux models. In the presence of time reversal, U (1) charge conservation and magnetic translation (with π-flux per unit cell) symmetries, if a generic interacting Hamiltonian has a unique gapped symmetric ground state at half filling (i.e. an odd number of electrons per unit cell), it can only be a QSH insulator. In other words, a trivial Mott insulator is forbidden by symmetries at half filling. We further show that such a symmetry-enforced QSHE can be realized in cold atoms, by shaking an optical lattice and applying a time-dependent Zeeman field.
Realizing quantum Hall states in a fast rotating Bose gas is a long sought goal in cold atom rese... more Realizing quantum Hall states in a fast rotating Bose gas is a long sought goal in cold atom research. The effort is very challenging because Bose statistics fights against quantum Hall correlations. In contrast, Fermi statistics does not cause such conflict. Here, we show that by sweeping the integer quantum Hall states of a spin-1/2 Fermi gas across the Feshbach resonance from the BCS side to the BEC side at a "projection" rate similar to that in the "projection" experiment of fermion superfluid, these states can be "fused" into a bosonic quantum Hall states. A projection sweep means the pair association is sufficiently fast so that the center of mass of the pair remains unchanged in the process. We show that the fusion of integer fermion states with filling factor ν ↑ = ν ↓ = n will result in a bosonic Laughlin state and Pfaffian state for n = 1 and 2. The is due to a hidden property of the fermionic integer quantum Hall states-for any grouping of opposite spin into pairs, their centers of mass automatically assume a bosonic quantum Hall structure.
Motivated by the recent discoveries of spin-1 and spin-1/2 Bose gas, we have studied the general ... more Motivated by the recent discoveries of spin-1 and spin-1/2 Bose gas, we have studied the general structure of the Bose gases with arbitrary spin. A general method is developed to uncover the elementary building blocks of the angular momentum eigenstates, as well as the relations (or interactions) between them. Applications of this method to Bose gas with integer spins (f = 1, 2, 3) and half integer spins (f = 1/2, 3/2) reveal many surprising structures.
We propose a simple scheme for generating rotating atomic clusters in an optical lattice which pr... more We propose a simple scheme for generating rotating atomic clusters in an optical lattice which produces states with quantum Hall and spin liquid properties. As the rotation frequencies increases, the ground state of a rotating cluster of spin-1 Bose atoms undergoes a sequence of (spin and orbit) transitions, which terminates at an angular momentum L * substantially lower than that of the boson Laughlin state. The spin-orbit correlations reflect 'fermionization' of bosons facilitated by their spin degrees of freedom. We also show that the density of an expanding group of clusters has a scaling form which reveals the quantum Hall and the spin structure of a single cluster.
We consider the condensate wavefunction of a rapidly rotating two-component Bose gas with an equa... more We consider the condensate wavefunction of a rapidly rotating two-component Bose gas with an equal number of particles in each component. If the interactions between like and unlike species are very similar (as occurs for two hyperfine states of 87 Rb or 23 Na) we find that the two components contain identical rectangular vortex lattices, where the unit cell has an aspect ratio of √ 3, and one lattice is displaced to the center of the unit cell of the other. Our results are based on an exact evaluation of the vortex lattice energy in the large angular momentum (or quantum Hall) regime.
We show that, apart from a difference in scale, all of the surprising recently observed propertie... more We show that, apart from a difference in scale, all of the surprising recently observed properties of a degenerate Fermi gas near a Feshbach resonance persist in the high temperature Boltzmann regime. In this regime, the Feshbach resonance is unshifted. By sweeping across the resonance, a thermal distribution of bound states (molecules) can be reversibly generated. Throughout this process, the interaction energy is negative and continuous. We also show that this behavior must persist at lower temperatures unless there is a phase transition as the temperature is lowered. We rigorously demonstrate universal behavior near the resonance.
We show that the quantum evolution of a spin-1 Bose gas with nearly all bosons initially in the F... more We show that the quantum evolution of a spin-1 Bose gas with nearly all bosons initially in the Fz = 0 state has a "quantum carpet" spin-time structure with self-similar properties. The system continuously evolves into "multi-peaked" Schrödinger cat like states, returning occasionally to coherent structures, which leads to large number fluctuations (as seen in recent experiments). The self similar behavior allows one to reveal the quantum evolution as a set of peaks in the number probability distribution of a spin component at times much shorter than the quantum revival time. We also show that these features survive small number fluctuations among spin components up to a few percent.
At present, there is a worldwide effort to use cold atoms to simulate strongly correlated quantum... more At present, there is a worldwide effort to use cold atoms to simulate strongly correlated quantum many-body systems. It is hoped that these "simulations" will provide solutions to many unsolved problems. However, the relevant energy scales in most of these experiments are so small that one has to go to entropy regimes far below those achievable today. Here, we present a general scheme to extract entropy directly from the region of interest. The late stage of this process is equivalent to a continuous "evaporation", and is able to combat intrinsic heating of the system. For illustration, we show how to cool a weak coupling BCS superfluid (with Tc ∼ 10 −10 K) to 10 −11 K with this simple procedure, with entropy per particle as low as 5 × 10 −4 kB in the superfluid region.
We show that when the Fermi energy of a Fermi gas is much smaller than the intrinsic energy width... more We show that when the Fermi energy of a Fermi gas is much smaller than the intrinsic energy width of a Feshbach resonance, the system behaves like a Fermi gas with a contact potential. This in turn implies universality at resonance, and large fermionic pairs in the strongly interacting regime. Recent experiments of JILA[1] and MIT[2] turn out to be deep inside the universal regime, which explains the perfect fit of these experiments by the BEC-BCS crossover theory with contact potential[3]. We also show that rf spectrocopy can be used to map out the pair wavefunction directly.
At present, many laboratories are performing experiments to simulate theoretical models of strong... more At present, many laboratories are performing experiments to simulate theoretical models of strongly correlated systems using cold atoms in optical lattices, a program referred to as "Quantum Simulation"
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Papers by Tin-Lun Ho